Long time lurker here who has read enough on this web site and from Pelican Parts book to undergo repairing my blown head gasket myself. I have learned a lot from reading your posts or at least enough to remove my intake manifold and remove my cylinder head at this point.

The patient is an automatic 1996 328i with 113K miles that suffered a failed water pump and pretty good overheating cycle while my Son was driving it.

Water pump, thermostat, thermostat housing were replaced and leak down test confirmed the head gasket was blown. I just took the head to the machine shop today. Machinist stated he could straighten it, deck it, pressure test it, and do a valve job.

I am writing to get everyones opinion on what else I ought to do while I have everything torn apart. I plan on the following:

1) Head gasket repair
2) Transmission service (Fluid is black from overheating)
3) Fuel injectors sent out to be cleaned and calibrated
4) New fuel filter
5) Brake light switch (I had ordered this before blown gasket)
6) Flush radiator

Should I:

Replace both timing chains?
Replace chain tensioners?

What else? Any advice greatly appreciated.

Scott

You may as well do the chains and tensioners while your in there, you won't have a better chance. Obviously you should use all new gaskets as well, often you can buy kits that include all the gaskets for the top end. New head bolts are generally called for and are a good idea. That said, I have reused head bolts before and never experianced a problem, but changing them is a good idea.

If the accessory drive belt(s) look bad, replace them too. Change your oil in case it was contaminated. Check the PCV system and fix as necessary. If the coolent was baldy contaminated (baby s**t) then all the coolent lines and expansion and probably the radiator should be replaced. If the coolent looked more or less okay, just change the hoses if they look bad. Make sure all the vacuum and fuel lines are okay when you reattach them.

Thats all I can think of for now. Just remember that it's easier to change stuff now with everything disassembled.

You may as well do the chains and tensioners while your in there, you won't have a better chance. Obviously you should use all new gaskets as well, often you can buy kits that include all the gaskets for the top end. New head bolts are generally called for and are a good idea. That said, I have reused head bolts before and never experianced a problem, but changing them is a good idea.

If the accessory drive belt(s) look bad, replace them too. Change your oil in case it was contaminated. Check the PCV system and fix as necessary. If the coolent was baldy contaminated (baby s**t) then all the coolent lines and expansion and probably the radiator should be replaced. If the coolent looked more or less okay, just change the hoses if they look bad. Make sure all the vacuum and fuel lines are okay when you reattach them.

Thats all I can think of for now. Just remember that it's easier to change stuff now with everything disassembled.


Thanks GrahmRH

How hard and what is involved in replacing the primary chain?
The coolant wasn't to bad. I think I am going to just pull the one year old radiator and flush it out real good.

Anyone else care to give me some advice?

I've never done a chain on one of those motors, so I don't really know. You will need to take the front covers off. The most important thing is to make sure the cam timing is correct, and ALWAYS rotate the engine by hand before you try to fire it up. Best thing to do is buy a manual for the car, it should tell you everthing you need to know

Definitely get new head bolts. BMW uses stretch bolts and they are one time use only.

There is no need to replace the timing chains, i've never seen one wear out. The secondary chain tensioner may be something to think about, they can get noisy with age. The primary chain is quite a bit more work to get to. Pulling the
front cover can be a real pain, just leave it alone.

You may want to replace the ICV while the intake is off. When I did the head
gasket on my boys car I went ahead and disassembled the head, put it in the
parts washer. Wire wheeled all the deposits off the exhaust valves and replaced
the valve seals and retainers. Maybe a bit overkill, but the car runs amazingly
smoother than mine now(both 95 M3's).

post back on this thread, preferably with pictures when you get underway. I'll be following in your footsteps- along with a cam swap pretty soon.

Replacing the tensioner's is something you want to do for sure, and chains aren't such a bad idea. They don't wear MUCH but its a cheap thing to do and pretty easy (on a lift at least.)

Get yourself a set of cam locking tools, they are required. And I would tear the head down, get it surfaced, throw in new valve seals, and either machine the valves or hand lap them at the least. And for sure wire wheel the valves, just be careful about it!