Leaky coolant

cozzie55

Hi folks

Got an error message on my bmw e90 for low coolant levels. I checked under the bonnet and it appears the reservoir tank was empty. (Id had some work done to the engine last week so I was assuming they'd emptied the coolant and not replaced) I topped up the coolant last night to the required level and ran the car for a minute.

This morning got into the car drove for about 5 minutes and the low coolant level light came on again. I checked under the bonnet and there doesn't appear to have been any major leak that could have lost a lot of coolant. Also There wasn't any large pools of coolant under the car this morning when I pulled out of the drive way. I can't check the reservoir level just yet as the car is still warm.

Question is..... if the reservoir is filled does it take some time for the coolant to get sucked into the engine? I.e. Could it be that coolant level drops when the engine runs for a few min? Or do you think I have a large leak somewhere?

Toyotafanboi

What work was done on the car? Do you know that they needed to remove the old coolant?

Going through 2x reservoirs (1000ml?) In a short space of time I'd say it's highly unlikely that you don't have a leak. You may not necessarily see a puddle under the car if the car has an undertray.

Have you got hot air in the cabin?

cozzie55

Toyotafanboi wrote: »

What work was done on the car? Do you know that they needed to remove the old coolant?

Going through 2x reservoirs (1000ml?) In a short space of time I'd say it's highly unlikely that you don't have a leak. You may not necessarily see a puddle under the car if the car has an undertray.

Have you got hot air in the cabin?

I had the transmission and clutch done and a service. I'm not sure why the coolant would have been removed. It was just the first conclusion I jumped too.

I had no hot air last night prior to refilling. Had plenty hot air this morning after the fill

Would it not have to be a pretty huge leak to empty in the space of 5 minutes running the engine?

Toyotafanboi

Without knowing the specifics of that particular car it could be the case that they'd need to remove a coolant hose to move things around do the clutch job. On the other hand you could just be unlucky and have a stone through your radiator etc.

I'd check back in with the people who did the work in a non accusatory way. That's if they aren't that far away and the car can make it. If you fill the reservoir once more and you only get 5 minutes out of it again then I wouldn't drive the car, you could easily do far more damage.

If there is a coolant hose split or with a loose clip or a punctured radiator, the car could easily pump out a lot of its coolant over just a few minutes.

If the car is losing half litre of coolant every 5 minutes it's unlikely that it's being lost internally through the likes of a head gasket issue as the car would be running terribly, if at all.

Alanstrainor

I'd agree, you have a leak somewhere. I wouldn't think it would be likely that they emptied the coolant to do the service, especially given that you have filled and re-filled the reservoir. It is worth noting that it is generally not as simple as just filling the tank if it was simply not refilled, you would have to bleed the system when doing this, or else you would have air pockets in the system.

Anyway, I would not drive the car as you risk overheating the engine which could spell the end for the car. Best to contact you mechanic I would say.

cozzie55

There is an air bleed valve on top of the reservoir which I would have thought would bleed the air.
I'll fill it again with coolant this evening and I think I'll be driving it straight to the garage for a check up.