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Engine shake after Engine Removal/Head Gasket replacement


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if you have hydraulic lifters they may have drained some fluid during the TB change depending upon how much you rotated the engine to find TDC etc. in which case the car may run rough and/or noisy for an hour or so. this is what my literature says and i'm in the middle of a TB change myself.

 

99 leg l sedan 2.2l 5-sp

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Yes, I did put back pressure plate in same orientation with flywheel - no clutch shudder that I can feel - depressing clutch pedal makes no difference.

 

Timing - I doubt it though it is not impossible.

 

Why I think timing is right - First, the car runs great. Second, I counted the teeth on timing belt(from crank sprocket mark to cam sprocket mark, and intake to exhaust cam sprocket marks) and they were exactly as per spec. As I understand it, only reliable way is counting teeth. The Right cam marks aligned perfectly with inside right timing cover....

 

The "not impossible part" - The marks on left intake cam sprocket did not align perfectly with left inner timing cover - seemed off by less than 1/2 tooth. If I had tried moving to next teeth, I would be off by more than 1/2 tooth and more importantly, the teeth count would have been off.

Mark on left exhuast cam sprocket was off by even less - perhaps 1/4 tooth. The left intake and exhaust alignment with respect to each other (the double etched marks on sprockets) seemed off by 1/2 tooth in relation to each other but the factory paint mark(not sprocket marks) going across left intake and exhaust were in perfect alignment.

 

I also suspect that a resurfaced head and an updated head gasket (Subaru redesigned them) with different thickness can make material difference to alignment with relation to inner mark, since they impact the distance between the crank and cam sprockets.

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I did have a CEL scare after HG replacement.

 

 

http://www.ultimatesubaru.org/forum/showthread.php?t=27635

 

I did measure compression on 1 and 2 and it seemed to around 200psi after 6-7 cranks. I didn't do 3 and 4 since they are harder to reach with engine in the car. Spark plug wire resistance measures up okay too. The plugs seem okay. I checked the injectors too and they were fine.

 

Somehow the CEL problem went away mysteriously.

 

Any other ideas? Could it be mechanical - I redid the pitching stopper but didn't make a difference. Engine mounts seem okay too...

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To ensure that timing belt hadn't skipped a teeth, I took out the left and right timing covers (center cover is blocked by crank pulley). The timing belt seems still fine - The marks on cam sprockets are still as I left them when I first installed it. 105.5 teeth count between left and right cams which is spec for my EJ25 DOHC - Since I can't measure from cranksprocket, this is the next best thing.

 

Spark plug wires - I did the experiment in dark garage - no arcs visible even when I spray with water/lysol!

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How can I tell if engine or transmission mount could be the reason for engine shake ? I can only see engine mounts (the one sitting on front cross member) visually, can't see anything else without first raising the engine... Could loose transmission mount cause engine shake? How would I check that?

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In a pushrod engine, that might be true. In an overhead cam engine, like the one we're talking about here, that's impossible. The relationship between the camshaft and followers will not change.

 

On the EJ25 DOHC, the head bolts are under the cam shafts, so it makes no sense to do the adjustment with the head off the block. Unless you don't mind disassembling the thing again to bolt the head to the block...

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I adjusted the valves on the bench when I did the headgaskets. I just torqued the cams into the heads and checked the clearances. I won't say that the clearance couldn't theoretically change when the heads are reinstalled in the engine, but the change would be extremely small.

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The car is running great with no CEL. Plug wires are tight.

Engine shake is the only problem, feel it at idle. As I said Idle rpms are fine too...

 

Could the shake still be attributed to a problem in ignition or fuel system? Wouldn't a problem in those trigger CEL?

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The car is running great with no CEL. Plug wires are tight.

Engine shake is the only problem, feel it at idle. As I said Idle rpms are fine too...

 

Could the shake still be attributed to a problem in ignition or fuel system? Wouldn't a problem in those trigger CEL?

 

I think it would, OBDII systems are pretty good at detecting a misfire. Have you double checked the engine mounts?

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How does one identify engine mount problems?

 

The engine mounts that fit on cross member are tight - I torqued them to spec. It is hard to see if anything is wrong with engine weight on them - visually they look fine.

 

Is there a way of identifying mount problems short of lifting the weight off the mounts - which would mean I would have to raise the engine.

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I would just examine the mount closely with the engine running. You should see movement but it should be very limited. The only engine mount failure I have ever diagnosed was very evident, with a couple of inches of movement when gears were changed, so my knowledge is limited to that experience.

 

Have you tried pulling one spark plug wire at a time to see if the nature of the shake changes? If you find a cylinder where pulling the wire doesn't change anything, that's the one you want to examine more closely.

 

If you haven't I would do a compression test on all cylinders.

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I would just examine the mount closely with the engine running. You should see movement but it should be very limited. The only engine mount failure I have ever diagnosed was very evident, with a couple of inches of movement when gears were changed, so my knowledge is limited to that experience.

 

Have you tried pulling one spark plug wire at a time to see if the nature of the shake changes? If you find a cylinder where pulling the wire doesn't change anything, that's the one you want to examine more closely.

 

 

If you haven't I would do a compression test on all cylinders.

Nope I haven't tried removing one plug at a time. You mean try to find a cylinder with no compression or very low compression? Won't very low compression also trigger a CEL? If a cylinder has reasonable compression (even 40 to 50 percent of other cylinders), I would assume that removing the plug wire will change the nature of shake.

 

I am thinking about doing it on cylinder 2 and 4...it's hard to get that tube into spark plug hole with engine in the car!

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