Compression drop from front to back?

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May 14, 2006
I recently purchased a non-running 85 4Runner, 22re. The owner said it had been running fine, but overheated and now needed a head gasket. The gasket on the timing cover looked somewhat new, so decided just to do the head and get a valve grind and new seats seals etc... So have re-installed the head etc... after doing a compression check, I get numbers of 165-155-150-145 front to back. I realise they are within the manuals recomended "tolerances", but what should I learn from this, are these numbers a problem?

Then out of curiousity, I decided to drop the oilpan. I know now that I should have done that in the first place. In the bottom of the oilpan, I found chunks of timing chain guides. Should I be worried, or can I assume they had done the timing chain before and these were leftover chunks that didn't get removed when the work was done? Any ideas
Obviously, just for future references......

That stuff will get sucked into the pickup skreen and starve the engine of oil.

Running W/o knocking I'd say just replace the bearings, if they apeare bad. (can do inframe)

NOT recomending on the pistons/ rings though.
I have since cleaned out the oilpan completely and given her a fresh coat of paint. Most of the chunks were larger pieces, but I made sure the pickup was clear anyways.

Bearings? Which ones, how do I know if they look bad?

Not recommending what on the pistons?rings?
or just not making any recommendations?
2MK, the rod's,....a friend that has done it says to take a "feeler" guage and push the upper parts over.

If it wasent his day off I'd call him he's a profesional mechanic AND I cant recall if he said you can do the mains or not. (forgot)

not recomending cause I dont know your (motor) condition or your prefrances.

me, if it runs, doesent knock or use more than @ 2-3 quarts between 3-5k mi. drive it till it dies (or can afford down time, two cars etc, ) and have a rebuilt one on a stand, ready to go.

How's O.P ?, And I would run 20-50 castrol


HOLD IT, HOLD IT, NMHO if you got IFS I would NOT do inframe, I would pull engine.

More room out side for: T.C / cover, oil seals, (head job) H.G, safty clean or garage rebuild, ?

Why do all this inframe and then have to do rear main seal? MHO

I have an 85 4r ret factory IFS and for future refrences.
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It's an 85..... So it's not IFS, but even if it was, I have and would again change the bearings with the engine it, it took my 5 hours start to finish to drop the IFS stuff and change the mains last year.

Pulling the engine is asking for too many little problems to happen......

And you can check the bearings but pulling the bearing caps off and looking at them, and if you are really into it you can plastigauge them to check the clearences. If I were you I'd change them anyway, it's only about $50 for new rods and mains.

You can change the rear main seal in a few hours by dropping the tranny....
Just tell me it's easier to pull the intake, head, change the whole Timing chain set,
instal the timing cover, remove/ replace the ext manifold, hot air tubes, in the engine bay, and then remove the trans to do a clutch and rear main?

I see your point can you see mine? :confused: :confused: :confused: :confused: :confused:

further more 2MK you can drop the oil pan in an SFA rig a whole lot easier than droping the diff on an IFS, thats why 2MK TC jobs 4x4 IFS are $900-$1,000+
for $60 worth of parts?

me I like to have the room even if it takes more time.

does it smoke?
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Ok, maybe I'm an idiot, and can't seem to connect what you guys are telling me to what I'm asking.

How does pulling the engine or not, doing the bearings or not, doing the main seals or not, relate to my compression numbers? What does a 20 psi drop from 1-4 indicate, and should I be concerned?

Secondly, how much water does it take to contaminate an engine full of oil?

I appreciate all the extra info, but a) The engine ain't coming out. b) I have already dismantelled and reassembled the top end, and I am not in the mood to start again. My oil pressure is ok, sitting at sortof the 1/4 mark when idling(factory gauge) but raises as I rev it. It does smoke lightly for the first 5 minutes or so, then seems to go away?

I am more than happy to run it till it dies, as that was the plan anyway. I just want to make sure it wont be something catastrophic in the first week!
The numbers are high enough, but the 165-145 drop is a little off the 10% difference they say is ok. It should run fine for a long time that way though. It doesn't take much water to turn oil into white goo, maybe around a half cup.... I dont' know for sure cause I haven't done any experiments! :D
seems it must have been the last of the goo fromvarious oil passages or what have you. The newest oil, 3rd batch, seems to be staying clear so probably good to go. It smokes very lightly for the first 5 minutes or so, then it seems to go away. I insure tomorrow, so will have first road tests etc to see how she runs under load etc...Does the fact that it smokes briefly but once warm goes away, tell me anything? Or rather, should it be telling me something?
Well, I decided to test my tps. Turns out that even though I put it back onto the throttle body exactly where I had marked, it was still off by a hair, and wasn't sending the right resistance when closed, that meant all the other settings were off, and I couldn't properly set my timing.

That being said, I still had to jump the "diagnostic"plug on the wire harness on the Pass. side fender well. The yellow two prong on the drivers side does nothing when jumped. So since my Toy is an 85, does this mean a newer engine has been put in already, or that 85 was a crossover year? Either way, once I jumped the terminal the idle dropped, and my timing was around 20 ABOVE tdc. So set it properly, tightened er up, and took it for a boot. Probably 4-5 times faster, and no hesitation or stumbling, super smooth.

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