coolant leak. we've got a coolant leak here

[leadtrombone]

Ok. So i am new to the forums.. been around the block in car mechanics a bit though i admit i am no guru...

My 320i touring is losing a lot of coolant. Though i do not notice any smoke out of the tail pipe and no dribbles on the driveway. There is oil in the coolant resevoir and coolant foamies on the oil cap and in the oil (i think).

I have recieved the opinion from (a third part and bmw) mechanics that these 6 cylinder engines are notorious for getting cracked heads. From what i have described do you thing this is more a head gasket problem or a head crack. I think in my mechanic knowledge that a gasket would show more smoke, and that only tells me more money to fix eh.

The real question is then, is a new head more cost effective than a new(rebuilt probly) engine or would it be better to drop a whole new block in.

thanks for the help...
[bmwkick]

 

[Big Daddy]

I have not heard anything about the sixes being "notorious" for cracking heads, although I had a 3.5 liter that blew a head gasket. I would guess a head gasket is the issue and you should have it checked for warp-age before reinstalling. A good time as well to rebuild the head. How many miles are on the car? Unless there are other issues, I would just rebuild the head.

 

[echothreezero]

Agreed. Headgasket failure.

If you continue to drive the car and let it overheat, that's when you'll see head warpage or cracks. Replace the gasket, get the head tested, and you're on your way.

 

[leadtrombone]

180000 km on the odometer. And i am very careful to watch the temps and keep the coolant filled...till i get the thing fixed


Thanks though. Any insights on a high idle issue. The car keeps idleing at around 1300rpms. The only times it doesnt was after a long autobahn drive and after being parked for about an hour and a half.....

vacuum leak maybe???

 

[Doughnut]

180000 km on the odometer. And i am very careful to watch the temps and keep the coolant filled...till i get the thing fixed


Thanks though. Any insights on a high idle issue. The car keeps idleing at around 1300rpms. The only times it doesnt was after a long autobahn drive and after being parked for about an hour and a half.....

vacuum leak maybe???

Just how much coolant are you losing from your coolant tank? I'd pull the head, send it away to be shaved and pressure tested, clean up the head mating surface on the block and throw a new gasket on there.

The m20 does not suffer a "notorious" head cracking problem (to my knowledge) do a compression test on the motor, and leak down test aswell IMO these steps should always be done prior to pulling a head.

Welcome to the forums! How's the weather over there in Germany??

 

[cliff]

coolant loss

have you checked your oil filler cap/dipstick for 'marshmellows', typically losing that much coolant will show up in the oil as a white substance. indicates coolant is getting in the oil, probably a head gasket, but might as have the head checked and cleaned up anyway as long as your're in there...good luck

 

[leadtrombone]

no "marshmellows" on the dipstick but on both the oil and coolant filler caps.. I am trying to figure out how much is going out. On the last long drive (lastweek) that i took when i drove at autobahn speeds (140-150 kmh) the rps were at about 400-4500 and it seemed after filling up the coolant it was about 45 minuts or so and the coolant light came on on the odb1 panel (above the rearview mirror). ~150 km and a refill... How ever on the way back (same trip) i kept the revs under 4k ~3000-3500 right after i toped it off and i made it about 2 hrs. After i got home and started the next morning the light came on pretty quickly.

It is really hot here right now btw.

would a head crack or a gasket leack also affect the vacuum. ???[???1] thanks for the info.

Maybe its just notorious in germany. this is the 2.0 liter m20 . i know in the states that that particualr engine (2.0liter) was not available at the time. only the 316, 318, 325.. i thinkg....

 

[Doughnut]

Pressure test the cooling system, do compression, and compression leak down test while your there.
What is the colour of your oil, turning into a milk shake?

 

[Big Daddy]

Yes a head gasket problem can affect vacuum. The coolant is not good for your rod bearings and you should not be driving the car.

 

[leadtrombone]

yes i know i shouldn't be driving the car. Hard to not to when you need to get to work and i don't have a spare. It sucks..

this week when i can get to the auto care center on post i will do the test and see what i can see. Problem is if i take of the head for the gasket and anythning else goes wrong that i cant get it together again, i am sans car..... aaaggghhh

The oil at this point doesn't look bad... it is not "foamy" in the sump. and i had a couple other eyes look at my dipstick and they did not seem to see anything wrong there. Then again you know what they say about assume...

.. so just to clarify. do a compression check, a leakdown test (is that where you put bit of oil in the cylinder to see if it changes the compression???) and pressure test the coolant system. -- what results am i looking for and what will they tell me about whats up...???

I ask the questions ahead of time as it is a public garage and i cant just pop on and ask. There are knowledgable ASE certified people that work there and can help, but i like to have as much info as possible. Sorry if i ask to many q's


also i filled up the coolant and the light came on about 113 km. i drove very conservativly andget rpms below 3500 the whole time. Don't think that that changes anything. But Fwiw thats that...

 

[cliff]

i'd plan on the old valve job. i'd reckon $1500 from an indy to do it right. Maybe 700 if you pull the head and take to a machine shop. my guess is you will end up one anyway. shopping around for prices is worth it though...good luck