Paging FastFred or any other BMW tech...question re: BMW 528 overheating problem

Dueller · 06-26-2010, 05:37 PM

Buddy has a 2000 BMW 528. He began noticing small loss of coolant. replaced the waqter pump, radiator, all coolant lines (including ones under the intake that required removal of the intake manifold, but not before it overheated briefly (like less than 2 minutes before shiutting it down).

Things seemed fine for a few weeks, then temps began to climb above the dead center in normal temp range on the gauge. When car sits for a few days it seems to start rough as water apparently gets in a cylinder suggesting blown head gasket. Has not run it up to red zone since all the repairs but its clear it is beginning to overheat intermitently.

This week he noticed for the first time small amount of oil in the radiator so we think headgasket is the problem.

Question: Should he attempt to change head gasket? Some say once the head gasket blows you must deck the block and head to properly repair because the 528 motor will warp head at slightest overheating episode. Or worse crack the head or block. Others have said you'll likely run into problems with studs. A gasket kit is only $250 and figure another $250 for special tools needed. He can pic up a 3litre motor for $1600 frrom a reputable salvage yard. He doesn't want to throw $500+ at repairing head gasket to not fix the car.

Any sugestions?

thanks

bell · bell's Garage

Well if he's going to go through the trouble of swapping engines I'd pop the head off anyway and inspect it......a good friend of mine had this happen and simply swapped the head gasket and he's still driving it....maybe he got lucky?
I can check with our bmw guy monday, I mainly wrench p-cars

mattdavis11 · 06-26-2010, 07:48 PM

I'd certainly change the fan clutch. It's probably the reason he's in this position.

asphaltgambler · 02:38 PM

Deuller - your friends BMW has a common issue; headgasket is failing. As long as the engine did not severely overheat a gasket replacement only is safe. The problem is he will need special cam-timing tools specifically for this series engine + there is a specific process to time the cans. If he doesn't have access to both- leave it to the pros

nocarrier · 06-27-2010, 03:09 PM

Been through this a few hundred times

Probably cylinder number four. Pull the plugs after the car has been sitting and you will probably see water inside there.

The heads usually crack near the exhaust valve on cylinder 3 or 4.

Forget having it fixed, find a good used head. I don't care what anyone says, I have never seen a repair on one of these heads last. I think it has something to do with the alloy.

I can't remember ever having one that was just the head gasket. Sorry.

I have been an ACT certified BMW Tech since 1994.

Furthermore, what happens when these cars overheat, is the head warps and pull the bolts out of the block.

The cast iron blocks usually survive this, the aluminum ones, usually not.

If you have the aluminum block, I would loosen the head-bolts, and re-torque them to see if the threads in the block hold. Then, pull the head, replace, and be on your way.

crustychief · crustychief's Garage

I was able to set the dual VANOS in my brothers car without the fancy tools. It had overheated and blew the headgasket. I just took my time and triple checked everything against the Bentley.