Bad HG or a Cracked head??

[IronFreak]

Thank you for the tip, I will definitely try this. I would like to note that they guy I bought it from couldn't tell me if the timing belt had been replaced, so that's why I put it in the garage. there is oil leaking, and before I cleaned the block it looked as if it was below the head on the block. I was leaning towards a bad head gasket as I've been told there are two oil jackets that run through the block and the gasket might blow out. but I also know that if the cam seal is bad it can leak there. I tried to look into the head through the oil fill to see if the rocker shaft plugs are visible, but I didn't see them, are those even on a b25 head? I was reading the pelicanpart tech articles on replacing stuff, but I got to be careful as they seem to use e36 models with DOHC setups a lot.

[jlevie]

The first thing I'd do would be to chemically flush the cooling system. Then see if the coolant remains clean.

1) Get the front of the car 1-2' in the air on jack-stands.

2) Drain the coolant, remove the thermostat, and set the heater controls for
full hot. O-ring sealed thermostats require you to make up a temporary
gasket, which can be made out of pasteboard.

3) Add flush compound and fill with plain water. Then run the engine at normal
temperature as specified by the flush manufacturer (usually about 15
minutes at operating temperature). In cooler weather it may be necessary to
block off some of the air into the radiator to decrease the warmup time.

4) Allow the engine to cool until you can place your hand on the cylinder head
w/o discomfort. Drain the system and refill with plain water.

5) Run the engine for 10-15 minutes or until temp is close to normal.

6) Repeat (4) and (5) until the water drained from the system is clear and
free of debris.

7) Fill with coolant. It is best to dilute aiitfreeze with distilled water.
Tap water contains disolved oxygen and may contain minerals. Either of
which will reduce the lifetime of the coolant.

Notes:

You don't absolutely need to remove the thermostat, but doing so will allow
continuous flow through the radiator and will also make draining & filling
faster and easier.

Always allow the engine to cool to the point that you can hold your hand on
the cylinder head without discomfort. That will prevent scalds from hot
coolant and prevent thermally shocking the head when you dump the coolant.

Filling the system with hot water makes the process go faster and keeps from
having to run the engine a lot in a cold condition (rich mixture).

A rusty cooling system needs an oxalic acid flush. Kits for that (containing
oxalic acid and soda for neutralizing the acid) used to be available, but
arent now. 8oz of oxalic acid and 4ox of soda will treat a 1-1/2 to 2 gallon
cooling system. The procedure is like the above with an extra step 4 where the
soda is added before the series of fill/drains are done.

[IronFreak]

I'm pretty green when it comes to BMW's but not to the mechanical world in general. I fell in love with the e30's and after searching for a long time in my area I found one that was rust free (next to impossible in Nebraska on a 20+ year old car.) its a 1988 325iS, I literally stole it for a $1000 bucks. A lot had already been done to it but the guy I bought it from was mechanically illiterate. He couldn't tell me what had been done the the motor maintenance wise so I drove it straight home and put it in the garage. I was aware of engine problems when I bought it, it has the "thick milky" looking crap in the coolant system. What I thought was interesting was when I emptied the oil last night was it was perfectly clean, not one sign of coolant of moisture in it.



I'm going to do a leak-down test tonight and pull the valve cover, from a few post I've read that it's common for this head to crack between the 4-5 cam bearing channels I believe. But what do I know, that is why I'm posting on here. shoot me some feed back guys.

Thanks,