1997 328is Possible Head Gasket

**E36328iss** · 01-11-2019, 02:46 PM

I have a 1997 328is with 236k miles that has been running pretty solid recently, but its been eating through about a quart or so of coolant every week. The PO said there might be a cracked cylinder head about 2 years ago but it has not really proven that. In the past week it has been eating through oil bad. Took 3 quarts about a week and a half ago and now it took another quart. It always smells like coolant out of the back when i first start up. But, today when driving on the highway it started to overheat so i turned on the heat all the way up and got her home. I also noticed when pulling out the dipstick while the car is on, it makes a sucking sound. Same with the oil cap, and the engine starts shaking really bad. I also looked under the oil cap and noticed a small mixture, could be from condensation since its cold, but its just another sign pointing towards the head gasket. Was planning on doing cutring Head gasket with ARP studs, since i was thinking turbo soon. What do you guys think? Should i pull plugs and check compression? It also has had a few different codes from it running rich, i think its just a vacuum leak.

**ed323i** · 01-11-2019, 02:54 PM

If you smell coolant from the exhaust, that's a bad sign. Mixture under oil cap also not a good sign, but M52's often have that when you only drive small distances on a daily basis (not enough time to heat up and get all the water vapor out of the oil). I'd do a compression test, and if needed, a leak-down test.

Vacuum leaks should cause the engine to run lean, and then the DME, after getting feedback from the oxygen sensors, will command the injectors to inject more fuel to compensate.

Best not to drive anymore until this is resolved, because these heads warp quickly..

Have you checked oil for coolant residue, and the coolant for oil contents?

**ChuckDizzle** · 01-11-2019, 02:57 PM

Originally Posted by E36328iss

I have a 1997 328is with 236k miles that has been running pretty solid recently, but its been eating through about a quart or so of coolant every week. The PO said there might be a cracked cylinder head about 2 years ago but it has not really proven that. In the past week it has been eating through oil bad. Took 3 quarts about a week and a half ago and now it took another quart. It always smells like coolant out of the back when i first start up. But, today when driving on the highway it started to overheat so i turned on the heat all the way up and got her home. I also noticed when pulling out the dipstick while the car is on, it makes a sucking sound. Same with the oil cap, and the engine starts shaking really bad. I also looked under the oil cap and noticed a small mixture, could be from condensation since its cold, but its just another sign pointing towards the head gasket. Was planning on doing cutring Head gasket with ARP studs, since i was thinking turbo soon. What do you guys think? Should i pull plugs and check compression? It also has had a few different codes from it running rich, i think its just a vacuum leak.

There's no harm in checking compression. If it is in fact the headgasket, now you have the excuse to open it up and do all the turbo preparation with the cutring and ARP studs.

**E36328iss** · 01-11-2019, 03:50 PM

Right, I actually have a pic below of the oil cap. Have not drained oil or coolant just yet, I’ll start with plugs and compression and go from there. Oil stick doesn’t seem to have any coolant residue. As for expansion tank it doesn’t either. But I’m sure if I drain oil or coolant I can for sure see. I’ll see how it looks after plugs and compression.
Here is a pic of the oil cap and valve cover.
https://imgur.com/a/Hip0lhA

Did the valve cover around 2 years ago when I first got the got the car. Looks like it might be leaking oil through the seal, it’s possible it didn’t seal correctly cause I didn’t torque it. And I also wasn’t too mechanically inclined when I did it haha.

- - - Updated - - -

Not gonna lie I’m not as upset as I should be, I really needed the excuse to turbo lol. I also found that there is defiently a small coolant leak somewhere by the lower region of the expansion tank. Possibly from the radiator or below the expansion tank. Drops the smallest amount but I believe it’s getting caught by the plastic under the radiator. I also hear a hissing so it’s gotta be losing the pressure from somewhere. Gonna have to figure that. My plan is to redo cooling system, belts, and then do the head gasket, studs, have block resurfaced. Then get some boost going under the hood

**Eric93se** · 01-11-2019, 10:23 PM

Your head is cracked and warped. If you do just the gasket it will fail.

**E36328iss** · 01-11-2019, 10:42 PM

Originally Posted by Eric93se

Your head is cracked and warped. If you do just the gasket it will fail.

How would you know directly? Would it be possible to have it repaired if it is? Or would that mean new head. I would pay to resurface it before installing for sure.

**bluptgm3** · 01-11-2019, 10:52 PM

You should still confirm with compression and compression leak-down tests.
Then go from there, previous respondent believes you are pressurizing the coolant system from crack in head.

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**spyderg0d** · 01-12-2019, 06:59 AM

Usually, if you have made it this long that its a very small crack. Normally a small crack will only show when the engine is up to running temp, thecrack expands from heat expansion and spills coolant, creates a pressure drop between 2 cylinders sometimes via a 2 crack, and makes one cylinder literally suck coolant and thus oil into yhe other cylinder to be burnt. Your head is mostcertainly cracled if not in 2 spots, then warped between 2 cylinders. You wont know for sure from compression check. The only way is to pull the head and clean the piss out of it and have someone who knows what to look for at it. Heads are relatively cheap compared to other engines.

**Eric93se** · 01-12-2019, 04:12 PM

There's also a change you have bad ring failure due to your very high oil usage, which may have been from you excessive coolant usage over a long period. Like people were saying to do a compression check and then retest with a small squirt of oil to see if it improves. But the fact that your consuming so much coolant may give inaccurate results.

**spyderg0d** · 01-13-2019, 10:59 AM

Leak down test to see if compression is being lost,not a compression check to see if compression is being made. Very different tests for very different things. Js

**E36328iss** · 01-13-2019, 07:16 PM

Just pulled the first cylinders plug out and it has oil around it.... I believe that is from the leaking valve cover gasket. But is it possible my valve cover could be cracked? Since I did the gasket 6,000 miles ago. Could not be a head gasket after all... maybe just losing coolant by the radiator somewhere and losing oil from the valve cover. Still gonna remove all 6 plugs and try doing a compression test today and hopefully leakdown test tomorrow. Any opinions on the situation?