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For awhile, it's possible for compression readings to go up with age.................(carbon buildup)Part of the compression gauge variability is the Schrader valve. I lost 25lbs when I replaced the valve until I found a low tension Schrader valve (the specifically make them for compression testers)Hook up your gauge to a known pressure (passing pressure thru the Schrader valve) and compare.........
I am intrigued by these differences between gauges. What order did you do the tests in?
Equus, no name, milton then equus again, because I felt we didn't crank enough to get maximum numbers the first time. I think all the gauges looked about the same quality, the milton being the oldest from 1977, equus being the most recent, probably less than 10 years old. I think the difference in numbers can come from how far the thread goes in the spark plug hole, they all tightened different amounts. I am sure I have a 4th gauge somewhere, if I find it I'll make sure I test it too and post the results. I was always told the number is not always the most important, it is more about the consistency of the numbers.
1987 Toyota 22R. 346k Miles1 - 1552 - 1553 - 1504 - 155
What elevation did you record the compression test? Engine cold? Hot? What was the ambient air temperature?Gnarls.
Can I assume correctly that those are original miles?Gnarls.
Here were the steps I was taught to do proper compression testing. 1. Disable fuel and ignition 2.Hook up battery charger charger 3. Remove all spark plugs 4. Wide open throttle 5. 6-7 compression revolutions 6. Double check any suspect cylinders. 7. Preferably do when cold as heat can mask issues due to expansion.
so i finally got around to pulling the first set of plugs to see how they are burning, and check compression. This motor was build roughly 8000 miles ago from a semi local engine builder for 1300 bucks including a "rv" cam. Motor seems to run well, no issues other then slight oil consumption. averaging 19 mpg for my commuting which its La parking lots.'75 above sea level68 ambient temp95 engine tempall plugs removedthrottle open5 compression strokes per test.1-1402-1423-1444-140*disclaimer used a Hazard Fraught compression tester my snappy is missing everything but the gauge, haven't used it in years so got no idea how long that stuffs been gone =(
Hey cporche,What year and engine? 1989 (10/88build) 22reWhat oil weight are you running? 10/30How much is it using? 1 qt/500-1000 miles (it does vary quite a bit)Any smoke? none that i can see even on hot or cold start no smokeDo you know what parts were used to rebuild this engine? honestly no idea, did not research this engine builder nearly enoughWhat type of rings were installed - Moly or Chrome? unsureDo you know what the crosshatching spec was? negativeWho machined the block? in house machining at engine builderHow much maching was done - bored?, decked? unfortunately not sureBlock year? later 22re has the "laser" on the block but thats all i can tellWhat engine break-in oil was used? i dont remeber exactly what brand i remeber searching for many hours to find a high zinc breakin oil tho.What was the break-in procedure? was told 2k for 5 mins then varying throttle for 2000 milesWho's head? New or built? "new"Do you know what the cam profile is and who's cam? was told it was a 261 rv cam but i have no way to confirm, nor was i given a cam card.Just first thoughts...At 8,000 miles the rings should be seated. Those numbers are low, and could explain oil consumption.I assume your engine temp was 195F.Thanks,Gnarls.
... i havnt checked compression since the wet compression test that the engine builder asked for which was 180 across all 4
The "wet" test with oil in the cylinders is usually for checking for valve leaks. That test will obviously increase the compression numbers unless there is a bad valve, rings, or head gasket. In order to get a valid comparison, the wet test is typically done after an accurate dry test.Testing with another compression gauge will not make any difference if you are using excess oil, it may give different readings. With a previous reading of 180 in all 4 cylinders, the valves appears to be fine.What brand and type of rings were installed? wish i could tell youDid the engine builder explain how they honed the cylinders? something i'll ask him when i give the long block back to himHow much oil is the engine using in what mileage? it doesnt use a set amount of oil i can go 1000 miles and sometimes only use 1 qt, sometimes it will use 2 qts. there is probably a correlation to run time but i dont really track that.Gnarls.
..... what make me feel like the engine builder used cheap parts was the fact that most of the seals leaked and had to be replaced. the paper gaskets didnt fit right and both the front and rear seals pissed from start up. Threw a lcengineering front and rear seals in and a different gasket set and now doesnt leak at all.
... Atleast this time i'll be going with a list of questions and hopefully get some decent answers...
Hey cporche,If and when you decide to pull your engine and have your shop rebuild it, I would have an agreement, preferably in writing, what he plans to do, what parts you and he agree to use, how much labor he estimates, and how much time before he has your engine ready to re-install in your truck. I would want to know if there is any out of pocket cost to me. Since you and he will need to determine what caused the engine to use so much oil, or what components, machining, or specs/tolerances were possibly not correct - a technical failure analysis would be very interesting to learn.If it were me, until I figured out what happened, I would be congenial and accommodating in helping him with the rebuild, as long as he doesn't change his mind and tell you to go take a hike.Please keep us updated on when you decide to pull your engine and what happens.Thanks,Gnarls.
The 6-9 spec for valve lash is lighter than normal, sounds like an engnblder 261C? What did Are the rings moly or chrome? Make sure the ring manufacturer specs the RA on the cylinder hone.Have you checked your spark plugs for color? yes inspected the plugs a few months ago, that prompted the compression check, showed signs of engine oil burning (some deposits) however color indicated correct running mixture.Was a compression check done? Yes, after plugs were removed they were 140,142,144,140 Wet compression was about 175-180 across all 4 (engine builder requested wet compression test even though i offered cylinder leak down test)The gas mileage doesn't sound bad, considering. This was my reasoning for saying its not running too rich that its washing the cylinder walls down.Gnarls.
...As it currently stands he is saying the gaps for the piston rings are correct within spec. He said they are NPR piston rings. He said he is still currently looking to see exactly why the engine has low compression,(to see if they just never seated properly and is also my oil consumption issue)
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