Honda J35 V6 (J35Z4) Sludge and Cam Scoring
- Thread starter The Critic
- Start date
Yes! And the valves should be adjusted at appropriate intervals. 30,000 miles per valve adjustment.
I can only report what I was told. Guy is the original owner, has cases of Amsoil Signature Series in his garage (that I saw) and there was an Amsoil Ea oil filter on the car when I worked on it. Unfortunately the oil was already drained when I got there, so no oil sample will be available.
High maintenance engine. The valves must be adjusted regularly. The oil needs to be changed at 5,000 miles and the PCV valve needs changing at 24,000 to 30,000 miles. There are also likely metallurgy problems with the camshafts.
There is also a significant coating of sludge on the underside of the front valve cover - probably a golf ball sized amount if you were to scrape all of it off.
I cannot fully vouch for the prior oil change history, but it is true that these engines are extremely hard on oil for some unknown reason.
The camshaft issue is probably more metallurgy related.
The valve clearance does not need to be adjusted at 30K intervals. It is a 3-4 hr job (book time) for a valve adjustment. The exhaust valve clearance does get tight overtime on these engines, but 30K intervals is not necessary.
Thanks. The grit in the 1st and I think 3 or 4th pics...........how hard is it? Metal or carbon?
Soft goop. If you zoom into the valvetrain picture, you will see the amount of soft sludge on the 12-pt head bolts. I had to use a screwdriver and a blow nozzle to dig out/remove all of the sludge before I was able to fit the socket onto the head bolts.
How did the oil drain out? First sure all looks nasty, but there was oil, flowing oil. Would love to know the fuel %, viscosity.
The little shiny bits and flakes are soft?
He drained the oil, not me.
Are you referring to the bits in the picture with the scored cam lobe? If so, those are all soft gooey bits.
OK Thanks again - want to be clear that I am not doubting anything you report. And I do agree, this VCM version NOT for extended OCI's. The normal 3.5L V6 in our old 2006 had no issues 15-20K OCI's.
I agree, if this is a known issue on these engines than i think it could not be prevented with any extreme short oci or oil.
I guess that even when only very small pitting starts it allows a cavity where the oil can seep in and so it will not maintain an oil film and ruin it from there.
Honda are one of the few manufacturers that still use the valve train type where you have to adjust them and no hydraulic lifters. Due to their tight tolerances and generally good materials adjustment rarely has to be done according to schedule.
This has the least drag so fuel efficient and also more power, this can also maintain verry high rpms up to 9000 10000 rpm.
But isnt it possible that the follower/valve clearance was wrongly adjusted so the the follower/roller keeps constant pressure on the lobe?
This probably wipes away the oil film/cause premature wear and heat which can also cause pitting.
Im not sure it is hard on oil, the non DI one specifically.
The belt takes a grip of shear out of the system.
The di pump adds in some shear, but a scan of the available UOA's on the board show that when following the maintenance minder none of them came back showing the oil unserviceable.
If the exhaust valve had moved so far up as to ride on the base circle and that much heat were present the valve would have burned.
I think this is bad heat treating or a bad batch of metal.
Agreed. Valve covers have never been removed on this car until now.
I did a quick search and seems like you could expect oil consumption and major fuel dilution with this engine ...
Not a cure for bad design; however, I would go for a short oci and thicker oil (good syn) with low Noack plus working/clean pcv as mentioned ...
Not a cure for bad design; however, I would go for a short oci and thicker oil (good syn) with low Noack plus working/clean pcv as mentioned ...
True but iam not sure if it was exhaust valve?
How about only a slight too small clearance.
a few people feel the way you do... but IMO, a guy who would bother paying for amsoil oil and filter, stock up on it, probably cares about his car enough to change it out at least once a year.
Their typically isnt enough heat on the intake side to cause damage you just get no compression in that hole.
The exhaust valve always pounds up into the head at a faster rate than the intake.
Unless you have a soft seat or a bad head by the time the intake closes the lash to 0 you've lost a bunch of exhaust valves.
Either way the vehicle will run like absolute crap if the valves aren't closing fully.
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