just fire it up or do a compression test mas how many klicks has it done ,just take rocker cover off and have a look to see how much oil stain is on the inside of head
another way is what no is on the front timming cover is it a G 1 G3 or G5
Hi Guys,
Just bought a manual blacktop engine/gearbox package to put into an AE86. Just did a leakdown test on the engine.
Cylinders 1 and 2 are showing less than 10% leakage
Cylinders 3 and 4 are showing 60% leakage.
Before I start pulling apart the engine and voiding any warranty I have, is it possible the VVTi system is holding the valves open? From what I understand, the VVTi system holds valves open on startup to drop compression. I was getting similar leakdown figures at TDC of the exhaust stroke, so am hoping the VVTi system is throwing me a curve ball here.
I have not connected the computer or battery to the engine, nor am I cranking the engine to generate hydraulic pressure.
I am using the leakdown tester correctly.
Any input would be appreciated
just fire it up or do a compression test mas how many klicks has it done ,just take rocker cover off and have a look to see how much oil stain is on the inside of head
another way is what no is on the front timming cover is it a G 1 G3 or G5
Do you have access to a bore scope ? Remove spark plugs and use it to look inside the bores and at the valves . Look for signs of rust or water marks etc.
Or you could carry out a "wet compression test " That is remove all spark plugs and use ATF in an oil can , add about four or five spquirts of oil to each cylinder , crank the engine over a few revolutions to spread the oil around. Then retest compressions to check for any increase in pressure.
I would also remove the cam cover and check the valve clearances , if you have very large clearances on 3 +4 you might have stuck or bent valves .
The front timing cover has a G1 sticker on it. Im not sure what milage the engine has done. Apparently, the engine was removed from a running car. Not sure how well the car run though.
I haven't connected the computer to it as the loom has been cut and I don't want to do any damage if it has been shorted at the cuts. I will connect up starter and crank it over and do a compression check.
I have a borescope and will try to have a peek inside. As I said, the engine still has warranty on it, and I don't want to give the supplier any excuse to void warranty if I start pulling things apart.
Will have a look today and post up results. Im still curious as to whether the VVTi system is contributing to the leakage.
vvti is only on when connected to power if 2 cyl are high and 2 are low .could be valves or shims etc also thats a 98 motor to 2001 so could be high kilometers . also check to see if belt has been changed ,that should give you some idea on klicks it has done
Todays results
Leakdown
Cylinder 1 and 2 less than 10%
Cylinder 3 50%
Cylinder 4 60%
Compression
Cylinder 1 and 2 - 180 PSI
Cylinder 3 - 20 PSI
Cylinder 4 - less than 5 PSI
I listened for leakage and Cylinders 1 and 2 were into the crankcase only. Cylinder 3 was mildly out the exhaust, Inlet and crankcase.
Cylinder 4 was heavily out the exhaust, and mildly out Inlet and into crankcase.
When the Leakdown test was done on cylinder 3 and 4, there was a noticeable leakage sound from the sparkplug areas, as if the fitting was leaking. Almost as though there is a crack in the head between 3 and 4. I fitted a spark plug into cylinder 3 while doing a compression check on cylinder 4 hoping there was simply a broken head gasket between 3 and 4, but no effect.
I had a look inside the cylinder with a borescope through the sparkplug, but couldn't get a good look at the valves. Will need to remove manifolds.
I removed the cam covers, and couldn't see any noticeable clearance between the cam and buckets, so assume visually that the valves are following the path they are supposed to.
Seems I have been ripped off severely by the importer I was dealing with. I will see how good their warranty service is, and if they don't honour it, will let people know. Might get them to refund a percentage of the cost and rebuild the engine.
At over $3200 for the package, Im a bit pissed off.
What were the Spark plugs like in condition & also for signs of fouling etc when you pulled them out .. Also if the Comp readings were like that when the motor was taken out from the Donor car the engine would not have even run, one cylinder with a low reading it would have just run, but not 2 cylinders like that ..
Also if the plugs had been in for a while & when you cracked them undone the carbon that has built up around the bottom of the plug will break off & if the valves are open I have seen the bits of carbon get deposited on a the valve seat which will effect the comp test & leak down test too until the Engine has actually started up & run & i have also seen valves stick on some Import engines that have been cleaned down after they were removed from the Donor car, but seem to come good once run ...
I would reccomend using feeler gauges to check the valve clearances , then you have an exact accurate measurement .
The more information you have will support your potential claim to the supplier .
I would suggest from what you describe the valves are not sealing on the cylinders in question .
The spark plugs all looked pretty similar without any noticeable carbon or fouling. I spoke with the supplier, and it seems like the engine hasnt been started for at least 8 months, I would say up to 12 months. My next step will be to remove the manifolds and have a good look into the ports with a borescope.
Engine, loom, computer, gearbox, cross member and brakes
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