E30 Engine issue(s)

[olietoledo]

I hate being made an idiot of. In this case, the monstrosity in my garage is having a field day with me.

It is an '87 325(i) California car. The title and VIN indicate a standard 325, the injection unit is decidedly i, but for the vagarities of California law, it's a 325.

On to the various maladies:

1) Engine overheating. I replaced the thermostat, only to discover that in doing so, neither the original nor the replacement thermostat fit in a way that will actually allow the engine to cool. I feel I am missing something in thermostat orientation class. Intermediate fix: omit thermostat (ohio has no known emissions controlls this close to Michigan, therefore my additional cold-start emissions will hardly beg a pip).

2) Engine studder/ lag. From other fine pieces of German engineering I've driven, this feels like it would be a fuel filter issue. However, I am gun-shy, as the last fuel filter I had to buy was $85.

Other vehicle information:
Odometer is permanently frozen at 229,949, and looks as if all of that was done five to seven years ago, after which it sat on a lot, waiting for the eventual migration to the mid-west. I've logged on an additional 45-100k on top of the stopped-clock figure, so my enjoyment of the vehicle is thorough. THe law of diminishing returns is another issue, as the tax write-off amount is very close to the purchase price.

I'd appreciate some friendly advice here. BMW types down here all tend to work for dealerships.

[sparticus1262]

Are you sure it's the thermostat?? I replaced mine in my 91' 318is and it turned out that was not the problem. I replaced the radiator and bled it properly an now it runs cool!! But if it is the therm. and if you got the correct piece for your car it should go on with no problem I would think?

I had the stutter problem also. I put in fuel additive(forgot which brand) which is suppose to clean out the fuel system and no more stuttering.