5-Series (E12,E28, E34, E39, E60)Chat relating to the BMW 5-Series of all generations. Specific models include: BMW 518, BMW 520, BMW 520i, BMW 530i, BMW 528i, BMW 530i, BMW 518i, BMW 524d, BMW 525i, BMW 525e, BMW 528e, BMW 540i, BMW 535i, BMW 520d, BMW 525td, BMW 525d, BMW 530d, BMW 525i/xi, BMW 530i/xi. (BMW 5-Series Forum)
HI guys i just bought this 98 528i automatic. The previous owner said the water pump and thermostat were just replaced and said it had some overheating problems, but just needed to be topped off with fluid and should be fine. I topped off the exp. tank and 5 minutes into my drive the temp started to sore.
When i got it towed back home checked it out.
-The oil doesnt appear to be milky
-Cant really see and contaminents in coolant.
-The car will not overheat at idle, only when getting up to speed
-The top hose is very hot, the bottom is cool
- When i leave the exp tank cap and bleeder off, the bleeder will let alot of gas out and i cant maintain a level in the exp. tank. I will add some fluid then it will overflow, and then the level will drop way down...
I fear this is a blown head gasket. Maybe the shop screwed up on the thermostat job? i sure hope so. I think the prev owner may be hiding something from me. ON the paper it said he went in for a coolant leak and then they replaced the pump and thermostat, and then maybe the overheating problem arised?... thanks for any suggestions theyre much appreciated!
Additionally, there is no visiable white smoke coming out the exhaust, atleast when its running at idle in my garage.
The check engine light is on ofcouse, i tried doing the diagnosis where you press the accelerater pedal 5 times but the light just stayed on and didnt do anything. Does that not work for this year?
How much coolant have you put into it so far?
Is the level still dropping or has it stabilised? It may be that they didn't purge the air out of it when they changed the water pump and thermostat.
It could be that the water pump that they installed is a cheap one that doesn't have the impeller fastened to the shaft properly. (Some impellers expand when hot and the shaft simply spins freely).
When its idling, what goes on with regards to the top and bottom hoses?
COuldnt find any good threads on air lock..... But i cannot maintain a level in the resovior. when i top it off, and then the engine warms, alot of gas spews out of the vent which pushes all the coolant out, and then the level will drop back down to low.
When starting it up from cold and just letting it idle, once the engine get ups to temp the top hose will suddenley get very hot and the bottom will stay cool. But the engine (atleast accorfing to the temp gauge) does not go a hair past midway when just ideling.
OK i just let the car idle for like 30 minutes with the bleeder cracked and air just keeeeeps bubbeling out, and im not really adding too much water except for the stuff thats spilling out of the bleeders i think. But both hoses are warm now... NOt a good sign i suppose
Bubbling IS NOT GOOD... You could have a air-line crack from a cylinder to the water-jacket causing carbon-dioxide to enter the coolant and create a geezer, or boiling effect !
I have mentioned on your other post that the M52 2.8 does have electric fans in front of the rad, but test the mechanical clutch fan too !!
Eso es todo! Please press the "REP" button if you are happy with your response/answer...
The AutoGuide.com network consists of the largest network of enthusiast-owned enthusiast-operated automotive communities.
AutoGuide.com provides the latest car reviews, auto show coverage, new car prices, and automotive news. The AutoGuide network operates more than 100 automotive forums where our users consult peers for shopping information and advice, and share opinions as a community.