What could cause my engine to seize?

[332]

Is this an SMG car or Manual?

[332]

The issue is the timing chain overhang is sealed against the head gasket. So if you remove the timing cover you could introduce a leak from the timing cover/block/head joint. I'd guess that is more of an issue with an old head gasket. If there ever was a situation where you could get away with not removing the head...it's this one.

You would need to remove the damper, replace the bolts and re-torque it which is a minor PIA. I still vote for removing the VANOS.

Fun fact, my damper is one I bought from you off e46 small world

[Darbshaw]

Wow you guys were on this last night. I'll try and recover as much ground as I can. I appreciate all of the feedback!

The issue is the timing chain overhang is sealed against the head gasket. So if you remove the timing cover you could introduce a leak from the timing cover/block/head joint. I'd guess that is more of an issue with an old head gasket. If there ever was a situation where you could get away with not removing the head...it's this one.

I can confirm that the little bit of rubber thats on the head gasket gets crushed significantly when you torque the head down to it. In this assembly I forgot to put gasket maker, and had to get a whole new head gasket. I'd imagine if I had the engine in car and wasnt mostly disassembled, I'd opt for the front cover only.

VANOS seems to be the biggest culprit at the moment. Thats an easy enough job and can probably squeeze this in after work today. I'm not confident this is the case, I'll try and explain my reasoning as best as I can.

1.

OP, when you installed the VANOS unit, did you push the splined gears attached to the VANOS pistons all the way into the VANOS unit before installing the VANOS unit on to the cylinder head?

• It looks like the post you referenced had this one step past where it needed to be. From what I can remember, I had to do a slight CCW rotation before inserting the splines. So the teeth should be correct, it doesnt hurt to check at this point

2. The vanos is oil pressure operated right? I doubt the engine built up enough pressure in the brief starter cranking to create enough pressure in the vanos to operate. I cracked the pressure valve later on in the day and no oil came out of it.


3. If there was piston to valve contact, wouldnt this be visible on a borescope? My only experience of contact is on a 7500 RPM explosion which is likely a lot more violent and this left significant signs of damage.

4. The engine has had countless turns at this point. The timing is locked, correct or incorrect if something made contact it would have done it early I don't see how it would wait until now to sieze.


Going back through all of this, the only thing that has changed from the last time I hand cranked until now is the flywheel, clutch, and trans. I'm leaning towards some sort of obstruction inside of the trans area, maybe a flywheel bolt backed out etc. Either way, pulling the vanos is a HELL of a lot less time consuming than dropping the trans or oil pan. Best case scenario we learn that the cams move freely and the problem is related to crank/trans area.

[jayjaya29]

I think the issue is with the clutch assembly. I put a clutch on backwards on my e36 a couple years ago and the clutch fused itself to the fork guide tube on the first crank. Motor was locked up solid. I had to cut access holes in the bellhousing to unbolt the pressure plate from the flywheel.

[sapote]

3. If there was piston to valve contact, wouldnt this be visible on a borescope? .

It depends on where you look. I think it's very hard using the borescope to see piston hitting valve in this case as there is no indentation marks created on piston top yet.
I wouldn't remove the vanos now, but I would verify the vanos timing first. But in order to check vanos timing, the crank has to go back to TDC.

Don't loosen any vanos hubs bolts.

1. Where are the crank and cams positions now? Post pics then maybe we can show how you get them back.

But if vanos timing is wrong causing pistons hit the valves, then why you can't turn the crank CCW back more than just a few mm? A bad vanos timing should not cause the crank only can turn a few mm in both directions.

[332]

I agree, its in the bottom end/transmission.

[sapote]

I think the issue is with the clutch assembly. I put a clutch on backwards on my e36 a couple years ago and the clutch fused itself to the fork guide tube on the first crank. Motor was locked up solid. I had to cut access holes in the bellhousing to unbolt the pressure plate from the flywheel.

This can be easily verified: as the clutch welded lock solid to the bolted down guide tube, then the crank is also locked down solid by the clutch, and so there should be zero movement when trying to turn the crank both directions. Not this case.

[jayjaya29]

This can be easily verified: as the clutch welded lock solid to the bolted down guide tube, then the crank is also locked down solid by the clutch, and so there should be zero movement when trying to turn the crank both directions. Not this case.

I was able to rotate the crank a small amount via the front crank nut. I'm sticking with it being a clutch/flywheel issue.

[Darbshaw]

This can be easily verified: as the clutch welded lock solid to the bolted down guide tube, then the crank is also locked down solid by the clutch, and so there should be zero movement when trying to turn the crank both directions. Not this case.

I agree that there shouldn't be and wiggle, but I think the welded clutch hits the nail on the head. Between school and work, I had no time yesterday for the VANOS but I'm hoping to attack the trans today. If the trans is a pain to remove, then I bet you this is my cause. I'm hoping that I can break it free without cutting into the bell housing. Any day to not use the welder is a good day.

I guess the welded clutch was really common on E36's when using an E39 M5 clutch, if you didnt install backwards of OEM instructions. I don't believe I mentioned this earlier, but it's the dead giveaway. My car has an E39 M5 clutch plate with a ZF 5-Speed. So for all that matters in this case, an E36 with an E39 clutch.

[jayjaya29]

I agree that there shouldn't be and wiggle, but I think the welded clutch hits the nail on the head. Between school and work, I had no time yesterday for the VANOS but I'm hoping to attack the trans today. If the trans is a pain to remove, then I bet you this is my cause. I'm hoping that I can break it free without cutting into the bell housing. Any day to not use the welder is a good day.

I guess the welded clutch was really common on E36's when using an E39 M5 clutch, if you didnt install backwards of OEM instructions. I don't believe I mentioned this earlier, but it's the dead giveaway. My car has an E39 M5 clutch plate with a ZF 5-Speed. So for all that matters in this case, an E36 with an E39 clutch.

Yep clutch plate installed backwards. You're in for a world of hurt getting it out. You can get 2 of the PP bolts out through the slave cylinder hole. Then the others must be accessed through a access panel cut into the side of the bell housing. Heres the openings I made:



Once you have 4 of the 6 PP bolts out then you will need to rotate the transmission in relation to the engine to get the remaining 2 PP bolts out.

Getting the clutch off from the guide tube is a whole other tub of fun involving 3 jaw pullers and sawzalls.

[sapote]

I was able to rotate the crank a small amount via the front crank nut. I'm sticking with it being a clutch/flywheel issue.

If the clutch was welded to the bolted down guide tube, then the crank still can be turned a few degrees due to the dual mass FW. For solid FW then zero degrees.
I should correct my previous statement.

[sapote]

Yep clutch plate installed backwards. You're in for a world of hurt getting it out. You can get 2 of the PP bolts out through the slave cylinder hole. Then the others must be accessed through a access panel cut into the side of the bell housing. Heres the openings I made:



Once you have 4 of the 6 PP bolts out then you will need to rotate the transmission in relation to the engine to get the remaining 2 PP bolts out.

Getting the clutch off from the guide tube is a whole other tub of fun involving 3 jaw pullers and sawzalls.

Cut up the bell housing like this destroys it. I would rather do this: turn the crank with a long bar to break the weld off or the guide tube. I will take this bet.

[jayjaya29]

Cut up the bell housing like this destroys it. I would rather do this: turn the crank with a long bar to break the weld off or the guide tube. I will take this bet.

Tried this, got nowhere. I had an 18" breaker bar on the front crank bolt and used a jack to extert pressure on the breaker bar, it raised the car off the jackstands.

[sapote]

I agree that there shouldn't be and wiggle, but I think the welded clutch hits the nail on the head. Between school and work, I had no time yesterday for the VANOS but I'm hoping to attack the trans today. If the trans is a pain to remove, then I bet you this is my cause. I'm hoping that I can break it free without cutting into the bell housing. Any day to not use the welder is a good day.

I guess the welded clutch was really common on E36's when using an E39 M5 clutch, if you didnt install backwards of OEM instructions. I don't believe I mentioned this earlier, but it's the dead giveaway. My car has an E39 M5 clutch plate with a ZF 5-Speed. So for all that matters in this case, an E36 with an E39 clutch.

With the welded clutch, crank only can wiggle if and only if the FW is dual mass.
Before diving in this hole, I would make sure I can hear the DM flywheel chattering when a helper rocking the crank, with tranny in neutral.

" I have about 1-2mm of wiggle back and forth"
If the crank pulley has 1 - 2mm wiggle, then it's not the case of a welded clutch, as the brand new DM flywheel has more rotation plays than this.

[Darbshaw]

So I have a single mass flywheel. I'm not entirely sure why it still has some wiggle to it. This is for sure friction welded on though.

I appreciate the help and this is most definitely the culprit. I haven't been able to confirm for sure as I just got my hole cut. I kept the hole as little as possible. The plan is to weld this back up and hope it doesn't sacrifice too much strength.