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quick help 97 OBW 2.5 186k tick - what oil?


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Not piston slap, not rod knock, sounds like a tick.

 

Just drained the old oil and would like to refill it very soon.

 

Anyone run into this?

 

5w50 + MMO (thin oil)

 

10w30+Lucas (thick oil)

 

Something in between?

 

Won't matter?

 

I'm leaning towards 10w30 by itself.

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In 97 I believe Subaru went to mechanical lash adjusters...Have the valves ever been adjusted or checked?....Personally I have a 96 with hydraulic lash adjusters.. I dumped in about half a bottle of seafoam (in the oil) and I havent had the ticking noise come back yet (its been months)...Sometimes small debris gets caught in the oil passages in the rocker shaft and blocks flow to the lash adjusters or a lifter just looses its prime from age...either way...I dont believe this is your case....Any maintaince history on the vehicle?

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Probably needs a valve adjustment, that's every 100k maintenance and most folks never do it.

 

Are you sure the tick is valve train or oil related? If so, the oil pump backing plate screws might be loose.

 

The tensioner could be bad too, they start ticking when the loose their tension and is a bit deceptive if you've never heard it before.

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No maintenance history.

 

OB99W - thanks for the links. The plug wires are secure but I'll check them again tomorrow.

 

No idea about the valve maintenance. But the genious who installed the non working PS pump stripped the threads of 2 bolts, the oil plug is oversized, and other tell tale signs of poor maintenance. Some glimmers of hope thought like lithium grease sprayed on the door check rods like dealers do at service intervals.

 

Tick seems to be coming from around cyl#4 and is noticable in the passenger compartment. I've heard enough piston slap and rod knock - and this aint it.

 

Another theory could be a slightly bent valve - like if someone broke the TB and threw a new one on.

 

At one time it did have a CEL for cylinder 3&4 missfire. I figured it was due to non Suby plug wires. I went to install used Suby ones I had but I didn't have the correct ones - the correct shape of the boot/grommet. That's why I know they were tight.

 

First one of these I didn't "redo" the engine on and/or replace the engine. Usually an OBW only lasts about 3 days when I'm done with it and I've had this one 3 weeks and 3 folks have looked at it. It's the cheapest one I've ever tried to sell by over 1k. It's got a whine like a wheel bearing in the rear. Diff is full (and was full when I checked it), can't tell which WB may be making the noise. Infact 2 old Suby techs and I all listened with a stethascope and it running 30mph on a lift and couldn't figure it out. This was after road testing it a few times. Some cars are possessed. Like the Forester I did in the fall. I seem to get one each fall (Skip wrote up the "mysterious Legacy from ell" or similar a few years ago). Perhaps I got one this spring as well.

 

I'm unlikely to fix the car if it requires head removel (which would mean engine removal for me). But I would like it to sound better if possible without compromising the engine. It seems to run fine.

 

But keep the suggestions coming - and thanks for the suggestions (and links) so far.

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OB99W - thanks for the links. [...]

You're welcome. Here's one more: http://endwrench.com/images/pdfs/2.5EngineValve.pdf

 

 

Another theory could be a slightly bent valve - like if someone broke the TB and threw a new one on.

Even a ''slightly'' bent valve probably won't fully seal, so it should be possible to find that with compression/leakdown testing

 

 

[...]It's got a whine like a wheel bearing in the rear. Diff is full (and was full when I checked it), can't tell which WB may be making the noise. Infact 2 old Suby techs and I all listened with a stethascope and it running 30mph on a lift and couldn't figure it out. This was after road testing it a few times. [...]

Are you saying that the noise is the same with the car running on the lift as it was on the road? Often wheel bearing noises are different when loaded versus unloaded, so if there was no change, what you're hearing may not be a bad wheel bearing. Is the noise related to road speed (change in pitch or level)? Does it vary if you get on and off the gas? If the noise shows up at relatively slow speed, find a deserted parking lot and try driving in tight circles to determine if the noise is different when turning right versus left.

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On the lift it's quiter(due to no load I'd assume).

 

The noise goes with the speed of the car (versus RPM of the engine, tranny,etc.). Makes same sound in neutral, starts at low sppeds - maybe 10 mph?

 

Sometimes it sounds like the RR wheel bearing, sometimes the LF. Someone was driving it last night and I sat in the back seat and stuck my head in the cargo area. Pitch changes whether slight turn or straight away but still can't tell. Actually when going straight it sounds most like RR. But when turning wither way sounds more like LF.

 

Car has some torque bind. No "at oil temp" flashing though.

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