Beetle knocking

rwbug

Any ideas what will be causing a very audible knocking noise coming from cylinder 4 on my 74 beetle? The noise disappears if I disconnect #4 spark plug lead. I have done all the basics I know like valve gaps, timing, plugs, leads etc

I am guessing it will be an engine out job which I am unable to do. I approached one local mechanic and he wasn't willing to take it on due to time and space it would take up, but he would fit a new engine if I sourced one. New engine seems a bit extreme to me - should I go this route? If anyone knows a mechanic willing to work on this in the North Cork area (Fermoy) - please let me know.

deckie27

rwbug wrote: »

Any ideas what will be causing a very audible knocking noise coming from cylinder 4 on my 74 beetle? The noise disappears if I disconnect #4 spark plug lead. I have done all the basics I know like valve gaps, timing, plugs, leads etc

I am guessing it will be an engine out job which I am unable to do. I approached one local mechanic and he wasn't willing to take it on due to time and space it would take up, but he would fit a new engine if I sourced one. New engine seems a bit extreme to me - should I go this route? If anyone knows a mechanic willing to work on this in the North Cork area (Fermoy) - please let me know.

Sounds like the engine need to come out and get pulled apart.

Pulling a bug engine is easy but a little trickier to get back in.

is there play in the crank?
Grab he front pulley and push it forward and back. If you can see or hear anything the case will need a rebore

I don't know anyone doing rebuilds in the fermoy area but there's a guy up north who is top class. But you would have to send the engine up to him.

Another option is to buy a reconditioned engine and have that fitted.

rwbug

Thanks deckie, I couldn't find and play by pulling/pushing the crank. Who would you recommend getting a reconditioned engine from or is it just a case of searching adverts/the bay etc?

deckie27

rwbug wrote: »

Thanks deckie, I couldn't find and play by pulling/pushing the crank. Who would you recommend getting a reconditioned engine from or is it just a case of searching adverts/the bay etc?

Contact this guy and have a chat.



http://bugbitz.com/shop2/

bugsntinas

I live in buttevant and have used a local garage by the name of cullens.over the years I've seen various classics in there,might be worth phoning them.if ya ever around this way i'd be happy to see if I can help at all.

rwbug

Thanks very much for the offer bugsntinas.

I have been looking at online shops at the price of reconditioned engines - pretty expensive at €1300+
Or is that reasonable?

kadman

rwbug wrote: »

Any ideas what will be causing a very audible knocking noise coming from cylinder 4 on my 74 beetle? The noise disappears if I disconnect #4 spark plug lead. I have done all the basics I know like valve gaps, timing, plugs, leads etc

I am guessing it will be an engine out job which I am unable to do. I approached one local mechanic and he wasn't willing to take it on due to time and space it would take up, but he would fit a new engine if I sourced one. New engine seems a bit extreme to me - should I go this route? If anyone knows a mechanic willing to work on this in the North Cork area (Fermoy) - please let me know.

What other symptoms does your engine have. Is it smokey, lack of power, hot starting issues. Is it a knock , or a tapping sound??

Based on a knock, its too early to go buying another engine at the moment, I agree with you there.

Do you feel confident enough to strip the engine, if it was taken out???

411 guy

i had my 1200cc engines insides rebuilt by a guy up north last year for about 800 euro, great job, and it kept my cars matching numbers(to the logbook) but i did have it removed and stripped down for him. he did collect it while he was down south,though. its not easy source a new 1200 crankshaft if thats needed, i'd imagine your noise could be (worst case scenario) big end bearings on that cyl's con rod,but if its been banging a long time it could have damaged the crank.

rwbug

Thanks for replies and sorry for not replying sooner. Proof that I am not a mechanic in the picture, I had managed to miss this despite lying under car looking at the valve gaps. Second set of eyes spotted it. Have new rods ordered.

Time to go watch some youtubes on changing them, and praying nothing else is damaged.

Kenny Logins

Has it actually bent? The tube (just an oil seal really) may be damaged. I wouldn't think anything else is..

deckie27

The most of been some gap on that exhaust valve.

rwbug

Kenny Logins wrote: »

Has it actually bent? The tube (just an oil seal really) may be damaged. I wouldn't think anything else is..

I have ordered new ones - will wait until they arrive before taking it out. Will do all eight and hope to set the gaps a bit better this time.

deckie27 wrote: »

The most of been some gap on that exhaust valve.

All my own work

Seweryn

deckie27 wrote: »

The most of been some gap on that exhaust valve.

Yeah, that is quite unbelievable. Never seen anything like it before. The other thing that comes to mind is the possibility of the push rod in that engine being used from a 1.3-1.6 engine in a 1.2 engine (the piston stroke on the 1.2 is shorter than on all other engines). If this is a 1200 ccm engine of course? You can check the engine number - if it starts with "D", it is the 1.2 engine.

Anyway, I would like to volunteer to properly set the valve clearances for you rwbug. I am not a professional mechanic, but I am a passionate ex Beetle owner, driver and a mechanic.
I was driving Beetles (had four of them) as my only cars for about 12-15 years and maintained, repaired and serviced them myself always, so I would be very happy to help you on this. Anytime you are in my area, you are welcome to pop in. I have the tools to do this simple job and it would only take less than an hour once the engine cools down. I could also check over the ignition timing, look over the cooling system and other bits around at the same time .

rwbug

The engine is a 1600, so I guess that rules out the shorter stroke theory - and leaves us with the theory that I made a complete mess of setting up the gap on number 4.

I am still waiting on parts to arrive but the main thing holding me back at present is lack of daylight. I am off work on Sunday so I hope to be able to get a look at it then and at least get it driveable.

Would be great to take you up on your very generous offer Seweryn. I guess I will be learning from the mistake I have made, but would be far preferable to pick up the knowledge from people like yourself willing to share the experience they have.

Seweryn

rwbug wrote: »

The engine is a 1600, so I guess that rules out the shorter stroke theory - and leaves us with the theory that I made a complete mess of setting up the gap on number 4.

My theory actually still stands here, as I made an error in the above post. I should have said that the engine may have a shorter push rod from a 1200 engine fitted. As your engine has a longer piston stroke, it may well be the case .

rwbug wrote: »

I am still waiting on parts to arrive but the main thing holding me back at present is lack of daylight. I am off work on Sunday so I hope to be able to get a look at it then and at least get it driveable.

Would be great to take you up on your very generous offer Seweryn. I guess I will be learning from the mistake I have made, but would be far preferable to pick up the knowledge from people like yourself willing to share the experience they have.

You are welcome . I am available most of the time, i.e. at late (dark) evenings or during weekends. I am based about 1h and 15min of easy driving from you, so not too bad. I hope I may have some old gaskets for the rocker covers (not sure), however when you order the parts just get a couple of sets of these together with oil sump gasket sets. They are cheap and always handy to have when you need to take a look under the covers or change the engine oil.

rwbug

I managed to get under the car this morning. Removed rocker arms and push rod, the push rod looked straight but fitted a new one anyway. Re-assembled and tried to set up valve gaps but couldn't on number 4 exhaust as the valve was stuck down. Tyre iron and wd40 released it and then was able to set it up correctly.

The engine is running extremely well now. Fingers crossed that valve isn't bent.

deckie27

Maybe a build up of carbon.
Try a drop of 2stroke oil in petrol and bring it for a long hard spin to get the temperatures up and blow out and ****.

The oil will help lube up the valves

mix 50-1 or more if you havent much petrol in the tank go for your spin and put in more petrol to dilute the oil down.


To much oil could foul the plugs on a cold start. Hence oil in for hot run and dilute for next cold start.