NCT Blew up the engine!!

Pierced Off

Father (78yo) had he car, diesel merc, in for the NCT. While the guy was reving it up for the emissions test, it went bang and started pissing out smoke. After the garage towed it in, it was initially thought to have been blown injectors caused by trying to bring it up to temperature too quick, now it seems that when they blew the injectors, they flooded the engine with diesel and damaged either the pistons or bearings, not 100% sure until the engine is stripped.
Question, I know that there is a waiver regarding timing belts but what comeback, if any, does he have in this case. At his age the car was supposed to last the rest of his driving days and he can't really afford to just scrap an 05, 220 diesel.

MarkR

If the engine failed by them revving it, there was something wrong with the car to begin with.

Vicxas

I think if the engine blew when the engineer revved it, then there was a very high chance there was an issue beforehand....

rex-x

Agree the nct didnt blow it up, something else was wrong with it.

Falcon L

Essentially, the NCT did it's job. Better the engine fail under test conditions than when passing a truck on a country road, or on lane 3 of a busy M50.

jimgoose

Falcon L wrote: »

Essentially, the NCT did it's job. Better the engine fail under test conditions than when passing a truck on a country road, or on lane 3 of a busy M50.

^^^
Correct. The car was in serious trouble before it went near the NCT centre.

swarlb

Not getting much sympathy here...if it's any consolation it's quite a common occurrence. I recently sold a 4WD, reasonable mileage for year, almost a years tax plus a years DOE (it only passed a few weeks prior to the sale). After taking the van for a test drive, the customer was happy and was about to close the deal. On the way back from the test drive, the engine developed a slight 'ticking' sound, which, by the time we reached the garage had developed into a full blown big end failure. Simple case of diesel mixing with oil and the results that follow. There is no way of knowing this will happen, as it's all internal. A simple thing like a copper washer or rubber 'o' ring can last 500k or 50k..
The NCT didn't 'blow up your engine'.

Pierced Off

The E220 has an econ diesel engine. After starting the car from cold, the engine adds more diesel than necessary to compensate for cold starting. Under normal driving conditions, with the engine under load, this extra diesel is burned off. When the car was revved from cold, the engine threw in the extra diesel it thought was needed for the revs, only since there was no load on the engine, it didn't get burned and instead flooded the injectors/ engine. When the mechanic took off the sump there was an extra 4 lts of fluid(diesel) in the engine oil. Surely, if the NCT were doing their job they would realise that you don't try to heat up a modern diesel engine in record time.

duffman3833

Pierced Off wrote: »

Surely, if the NCT were doing their job they would realise that you don't try to heat up a modern diesel engine in record time.

But is this not the same as starting your car and driving off straight away on a cold day. you could be going 60mph with a cold engine, unless the nct tester was red lining the poor car

Falcon L

Pierced Off wrote: »

The E220 has an econ diesel engine. After starting the car from cold, the engine adds more diesel than necessary to compensate for cold starting. Under normal driving conditions, with the engine under load, this extra diesel is burned off. When the car was revved from cold, the engine threw in the extra diesel it thought was needed for the revs, only since there was no load on the engine, it didn't get burned and instead flooded the injectors/ engine. When the mechanic took off the sump there was an extra 4 lts of fluid(diesel) in the engine oil. Surely, if the NCT were doing their job they would realise that you don't try to heat up a modern diesel engine in record time.

...which is why they ask you to present the car with the engine at working temperature. Why was it cold?

hytrogen

Get the mechanic to draw up a list of parts needed and Search adverts.ie ( ) or Done deal for second hand engine parts. No need to scrap the whole car if it's in pretty good nick otherwise..

Skatedude

But then a lot, lot more e220's would all blow their engines in winter when people often rev them in frosty cold weather to get the heating warmed up etc. There had to be a fault to begin with

Pierced Off

Falcon L wrote: »

...which is why they ask you to present the car with the engine at working temperature. Why was it cold?

Because he lives 5 minutes away from the test center and although the car was warm when he arrived on time, he was left waiting 30 minutes before they took his car in to test it, so it wasn't up to temperature when they started.

Pierced Off

Skatedude wrote: »

But then a lot, lot more e220's would all blow their engines in winter when people often rev them in frosty cold weather to get the heating warmed up etc. There had to be a fault to begin with

According to Mercedes, it's not warming up the car that's the problem, it's sitting with your foot at 5000 rpm in a cold car.

swarlb

Pierced Off wrote: »

The E220 has an econ diesel engine. After starting the car from cold, the engine adds more diesel than necessary to compensate for cold starting. Under normal driving conditions, with the engine under load, this extra diesel is burned off. When the car was revved from cold, the engine threw in the extra diesel it thought was needed for the revs, only since there was no load on the engine, it didn't get burned and instead flooded the injectors/ engine. When the mechanic took off the sump there was an extra 4 lts of fluid(diesel) in the engine oil. Surely, if the NCT were doing their job they would realise that you don't try to heat up a modern diesel engine in record time.

So did the van I was selling... so do a lot of them. Are you saying that after driving the car to the NCT, it sat there long enough to get 'cold'. The NCT's job (and I'm not defending them) is to check cars, their job is not to know the engineering aspects of every car they check. Years ago many cars had 'automatic' chokes that depended on the water reaching a certain temperature to shut off the choke. This usually depended on a tiny bimetallic 'spring' built into the choke mechanism, which was housed in a water filled unit attached to the carb. Over time, the spring rusted and seized, and very very few cars once they got a little old had a functioning choke. Which resulted in either non starting, or flooding.
The ECU in your Merc is more than capable of dealing with the issues you describe, otherwise there would be Mercs 'blowing engines' all over the place (and maybe there are, who knows).
You asked for advice, and the chances are you were simply unlucky. I doubt very much if that amount of diesel would have been pumped into an engine in such a short space of time, unless there was an inherent problem to begin with.
You could of course, ask NCT what they think.

gctest50

Pierced Off wrote: »

The E220 has an econ diesel engine. After starting the car from cold, the engine adds more diesel than necessary to compensate for cold starting.

just like most diesels for many years

if is so technologically advanced, it should have detected it was being revved up and cut back on the fuel etc

Pierced Off wrote: »

Under normal driving conditions, with the engine under load, this extra diesel is burned off. When the car was revved from cold, the engine threw in the extra diesel it thought was needed for the revs, only since there was no load on the engine, it didn't get burned and instead flooded the injectors/ engine.

no way it injected 4 litres extra

Pierced Off wrote: »

When the mechanic took off the sump there was an extra 4 lts of fluid(diesel) in the engine oil. Surely, if the NCT were doing their job they would realise that you don't try to heat up a modern diesel engine in record time.

MarkR

Pierced Off wrote: »

According to Mercedes, it's not warming up the car that's the problem, it's sitting with your foot at 5000 rpm in a cold car.

I'm pretty sure Mercedes would say it wasn't their fault the engine blew up.

If he only drove the car for 5 minutes, it wasn't warmed up properly. If the issue was the way that the NCT test cars, this issue would be widespread. It's not, so the issue is likely specific to the car.

Have you tried an independent mechanic?

rex-x

I suggest you find a new mechanic

Golfgorfield

I suggest you go argue with the NCT, you've had the same answer from every single poster here that its likely a car fault, yet you keep fighting back. Nobody on Boards can fix your problem. I mean the car problem.....

mickdw

Sounds like the issue is of the car owners own making.
If the car was fully warmed up when arriving at the test centre, there would be none of this cold engine issue to worry about.
The op seems to be an expert now on how to treat the engine but if this was known before, why not ensure the car was warm. Even a half hour wait wouldn't cool a fully warm engine.
I've said it before and I will say it again. A car engine that cannot withstand the test procedure is an engine that was ready to fail anyway.
How did 4L of fuel get to the sump over the couple of mins that they might be doing the revving?

Special Circumstances

Pierced Off wrote: »

The E220 has an econ diesel engine. After starting the car from cold, the engine adds more diesel than necessary to compensate for cold starting. Under normal driving conditions, with the engine under load, this extra diesel is burned off. When the car was revved from cold, the engine threw in the extra diesel it thought was needed for the revs, only since there was no load on the engine, it didn't get burned and instead flooded the injectors/ engine. When the mechanic took off the sump there was an extra 4 lts of fluid(diesel) in the engine oil. Surely, if the NCT were doing their job they would realise that you don't try to heat up a modern diesel engine in record time.

Can't be that modern if it can't figure out from RPM, air flow and fuel flow that there is no load on the engine!

jimgoose

Pierced Off wrote: »

The E220 has an econ diesel engine. After starting the car from cold, the engine adds more diesel than necessary to compensate for cold starting. Under normal driving conditions, with the engine under load, this extra diesel is burned off. When the car was revved from cold, the engine threw in the extra diesel it thought was needed for the revs, only since there was no load on the engine, it didn't get burned and instead flooded the injectors/ engine. When the mechanic took off the sump there was an extra 4 lts of fluid(diesel) in the engine oil. Surely, if the NCT were doing their job they would realise that you don't try to heat up a modern diesel engine in record time.

You're thinking of perfectly normal cold-start enrichment that every EFI - diesel or petrol - setup does. Do you mean to tell me the thing horsed nearly a gallon of diesel into the sump simply because some NCT fella gave it the toe in neutral?? Did it buggery like. Mercedes told you the right of it - this is a result of taking it near the redlline with a sump full of cold oil.

Paddy@CIRL

There's no way in hell that a five minute drive got it up to full operating temperature.

jimgoose

Special Circumstances wrote: »

Can't be that modern if it can't figure out from RPM, air flow and fuel flow that there is no load on the engine!

Of course it can. This is EFI 101.

Special Circumstances

jimgoose wrote: »

Mercedes told you the right of it - this is a result of taking it near the redlline with a sump full of cold oil.

Still though, I would think it shouldn't crap itself from a one off occurence of revving it from cold.

Gradual accumulation of 4 litres of diesel (in a sump usually holding 6? litres of oil) is the issue here IMHO.

Henry Ford III

Pierced Off wrote: »

Because he lives 5 minutes away from the test center and although the car was warm when he arrived on time, he was left waiting 30 minutes before they took his car in to test it, so it wasn't up to temperature when they started.

That doesn't add up.

It takes much longer than 5 mins to fully warm up a modern diesel. Probably 10+ minutes.

A fully warm engine will take a lot longer than 30 mins to go cold too.

slapper2

The nct centre generally has your car running 4-5 minutes prior to the emissions test between . They don't red line the cars generally.
Now flip it around. You mean to tell us that the car was started for 10 mins to heat up every time your father wanted to drive anywhere and the first time it wasn't the engine blew. I'm sorry but this seems to me to be a case of finger pointing and everyone else is at fault.
Modern cars are generally ****e in quality in comparison to the older cars. Over sensitive to slight changes. As the old saying goes ,they don't make them as the used to.
I recommend just look for a scrapped one and swap the engine.

jimgoose

Special Circumstances wrote: »

Still though, I would think it shouldn't crap itself from a one off occurence of revving it from cold.

Gradual accumulation of 4 litres of diesel (in a sump usually holding 6? litres of oil is the issue here IMHO.

Of course yes, I agree.

223vmax

Crux of the problem I think is this... Tester revs car to get temp up or tester puts boot to the floor, red lines the revs until engine failure.

If he red lined it and showed negligence then prove it - that's the problem.

bucketybuck

slapper2 wrote: »

Modern cars are generally ****e in quality in comparison to the older cars. Over sensitive to slight changes. As the old saying goes ,they don't make them as the used to.

Thats right, they don't.

They make them far more reliable than they used to.

Falcon L

Special Circumstances wrote: »

Still though, I would think it shouldn't crap itself from a one off occurence of revving it from cold.

Gradual accumulation of 4 litres of diesel (in a sump usually holding 6? litres of oil is the issue here IMHO.

Could be the result of a clogged DPF. Some (Most?, All?) engines dump diesel into the sump if the regen is stopped before it's finished. Could this be another case of a diesel engine bought when a petrol one would have been a better choice?

As an aside, my 2.0L diesel went through the NCT yesterday. The tester revved the ballix out of it. It didn't shoite itself, it just got on with the test and passed. 204,000 kms and it still feels like a newish car.

gctest50

Pierced Off wrote: »

The E220 has a......

the one in your anecdote has a bad mechanic/maintenance etc

or he should have bought a 123, doesn't seem bovvered by a bit of use

shietpilot

Once again, another diesel driver who doesn't actually know how to drive a diesel car.

The first thing I heard about diesel cars was:
1. You should make sure the engine gets up to operating temperature on every trip
2. Short driving is not suitable for diesels
3. Arrive at the NCT centre with the engine at operating temperature
4. Before the NCT kick the diesel engine's balls so get rid of carbon deposits in the exhaust

If you go to the NCT test centre in Fonthill, there is usually a queue of cars in the car park with owners getting ready to get their cars tested in the early morning. You will usually see that most are revving the tits out of their cars, especially if they're diesel.

I remember once seeing a WRX STI there, wow, that sound

galwaytt

Falcon L wrote: »

...which is why they ask you to present the car with the engine at working temperature. Why was it cold?

You can present it at working temp all you like : but if you're waiting for 40 minutes beforehand it won't be warm when they put it on the test lane..

shietpilot

galwaytt wrote: »

You can present it at working temp all you like : but if you're waiting for 40 minutes beforehand it won't be warm when they put it on the test lane..

As I mentioned earlier, in the Fonthill NCT centre you go in, pay for the NCT if you have to and bring the car around. You can sit in it until it's taken in.

galwaytt

223vmax wrote: »

Crux of the problem I think is this... Tester revs car to get temp up or tester puts boot to the floor, red lines the revs until engine failure.

If he red lined it and showed negligence then prove it - that's the problem.

There is no reason to red line it for any reason, they did the same with my sis in laws 323Ci . Reddened it in the lane - totally uncalled for. The test calls for 3500rpm iirc.

I want to put a 'valet' limit on my car for the next test

beauf

galwaytt wrote: »

You can present it at working temp all you like : but if you're waiting for 40 minutes beforehand it won't be warm when they put it on the test lane..

galwaytt wrote: »

There is no reason to red line it for any reason, they did the same with my sis in laws 323Ci . Reddened it in the lane - totally uncalled for. The test calls for 3500rpm iirc.

I want to put a 'valet' limit on my car for the next test

Would a combination of the car diagnostics and the car check in, test start time in the NCT centre, give figures to prove the car was waiting a long time, then rev'ed beyond the required, and manufactures limit.

Trojan

I recently did a 150 mile drive, pulled in and was immediately able to open the coolant expansion bottle cap to check the level. It was night, cold, and average speed was above 50mph the whole way so air flow must have kept it nice and cool. I'm not saying the coolant temp is the be all and end all, but this certainly indicates to me that the engine is at the lower end of the operating temperature range.

My point is that engine temperature can be cooler than you think for a long trip, or much hotter than you expect from a short trip stuck in traffic with the heat off. The whole "float" thing with the temperature gauge is misleading.

shietpilot wrote: »

As I mentioned earlier, in the Fonthill NCT centre you go in, pay for the NCT if you have to and bring the car around. You can sit in it until it's taken in.

Might be worth taking a second key to the test, and going back out to the car while waiting and letting it idle for a bit.

Special Circumstances

I think very simple maths might have an answer here.
Nct should refuse to test a diesel car that is under or over filled with oil.
If there was indeed a normal level of oil in going in the door, and 4L of diesel plus whatever of oil in afterwards....

Either the engine must have been literally overflowing with a 4L diesel / 5/6/7 L oil mixture afterwards, or what was in the sump beforehand was mostly diesel with very little oil and failure was only a matter of when, not if.

Anjobe

Special Circumstances wrote: »

I think very simple maths might have an answer here.
Nct should refuse to test a diesel car that is under or over filled with oil.
If there was indeed a normal level of oil in going in the door, and 4L of diesel plus whatever of oil in afterwards....

Either the engine must have been literally overflowing with a 4L diesel / 5/6/7 L oil mixture afterwards, or what was in the sump beforehand was mostly diesel with very little oil and failure was only a matter of when, not if.

The NCT manual does state that the smoke test should not be performed if the car is under/over filled with oil, and also if the engine has been warmed up by idling as this will lead to a higher smoke opacity reading.

Pierced Off

Special Circumstances wrote: »

I think very simple maths might have an answer here.
Nct should refuse to test a diesel car that is under or over filled with oil.
If there was indeed a normal level of oil in going in the door, and 4L of diesel plus whatever of oil in afterwards....

Either the engine must have been literally overflowing with a 4L diesel / 5/6/7 L oil mixture afterwards, or what was in the sump beforehand was mostly diesel with very little oil and failure was only a matter of when, not if.

The car was serviced 5 days earlier and had 6.5lt of oil in it, recommended amount and they have a digital oil gauge which showed that the oil level was correct.

mickdw

Pierced Off wrote: »

The car was serviced 5 days earlier and had 6.5lt of oil in it, recommended amount and they have a digital oil gauge which showed that the oil level was correct.

So you are saying that after 2 mins in the test lane with revs on that it feed 4L more than it was burning via injectors past the cylinders and into sump resulting in 10.5 L in the sump?
Good luck getting anyone to buy that one.

gctest50

Pierced Off wrote: »

The car was serviced 5 days earlier and had 6.5lt of oil in it, recommended amount and they have a digital oil gauge which showed that the oil level was correct.

If it was the NCT test(ers) fault then there would be a lot more e220s with blown engines

Special Circumstances

Pierced Off wrote: »

The car was serviced 5 days earlier and had 6.5lt of oil in it, recommended amount and they have a digital oil gauge which showed that the oil level was correct.

Interesting, that blows my gradual accumulation of 4L of diesel in the sump out the window.

So, 10.5L of fluid in the sump give or take after the incident. (6.5 + 4)
Yikes. 60% over the normal level.

Double yikes if that volume managed to get from the injectors to the sump in the course of seconds or tens of seconds.

What is the max flow rate of those injectors I wonder - how long would it take to fill 4L? Surely the engine would hydrolock if you tried to pump a volume of diesel greater than the actual cylinders capacity in less than a minute?

And why would a car **** the bed big style like this just because of a one off high rev when cold?

I look forward to hearing how you get on!

BohsCeltic

shietpilot wrote: »

As I mentioned earlier, in the Fonthill NCT centre you go in, pay for the NCT if you have to and bring the car around. You can sit in it until it's taken in.

You didn't the last time i was there.
You wait to be told where to park the car, go into office and pay and hand over the keys.
I've often been waiting 30 minutes before the car has been taken in.

alias no.9

Modern diesels have very high pressure fuel lines but injectors with tiny jets. If an injector were to disintegrate leaving a very open passage into the cylinder, its plausible that the high pressure pump would be capable of flowing a large volume quickly. You would imagine that some of the feedback signals from the various sensors would go out of range very quickly and shut it off however.

Anyway, if an injector did disintegrate, it was probably shagged in the first place and the NCT had little to do with it.

shietpilot

BohsCeltic wrote: »

You didn't the last time i was there.
You wait to be told where to park the car, go into office and pay and hand over the keys.
I've often been waiting 30 minutes before the car has been taken in.

That's why you go and pay first, then park the car and then... don't get out until they take the car in

Toyotafanboi

Pierced Off wrote: »

According to Mercedes, it's not warming up the car that's the problem, it's sitting with your foot at 5000 rpm in a cold car.

Probably the least relevant correction on thread, but i'd say that the car redlines way before 5k too.

BohsCeltic

shietpilot wrote: »

That's why you go and pay first, then park the car and then... don't get out until they take the car in

They asked for the keys when i was in paying during the summer

Toyotafanboi

Really depends how busy the centre is I guess. Last year the tester asked me to wait in my car in the car park que and drive it in myself.

This year I turned up 25 minutes early, tester took my keys and got it from the carpark himself and my test was finished before it was even due to start.

Same centre both times.

robtri

I think diesel injectors have a flow rate under load of roughly 45cc per min...

over 4 injectors, 180cc per min... so even at 50% burn and 50% being dumped into the sump, it would take over 40mins to put that much diesel into the sump.