CaptJohn

Pulled the heads off my 3.0, 1989, 53K miles because the compression was low in the center 2 cylinders. The head gaskets were fine. Valves look good except all the other exh valves were white, these two were dark in color, no sign of heat. I filled the cylinders up with trany flluid and none is leaking past the rings. Likewise, flipped the heads over and filled the valve chambers and no trany fluid is leaking by the guides. Prior to pulling the heads I adjusted the valves to make sure they were not tight, they were, adjusted and re-did comp check, no difference. Only 65 psi. What gives? any ideas? Hone marks are still on the cyl walls... I was expecting to see tuliped valves, somthing obvious....Capt John in NH

abecedarian

"valves look good except all the other exh valves were white"

huh?

can you post this and describe the valves based on which cylinder they represent?

CaptJohn

The two center cylinders are # 3 and 4. When I pulled the heads and rolled them over, cyls 1,2 and 4,5 all had discolored, or white looking exhaust valves. The (6) intake valves all looked alike, oily, but the 4 exhaust valves obviously get hot. On Cyl's 2 and 4 both the intake and exhaust valves have the same, darker, or oily appearance... odd...John

abecedarian

pics please...
ashy deposits on the exhaust valves are, for the most part, normal.
...but then you said #4 exhaust valves (#4 only has one exhaust valve)

how about a 'break down' of each cylinder by intake and exhaust?

vital22re

iTrader: (2)

if you add a couple capfulls of oil to the cylinders, does the compression increase? if not i'd say its something with the valves not fully seating. Pictures might help

CaptJohn

My mistake, (1) exh valve per cyl. Never posted a pic top this site, it asks for a URL....

93toyrunner

yea it is lame posting pics you have to down load them to a picture thing like photobucket which gives you a url then you put that url in. there is a sticky on it somewhere but unsure where

CaptJohn

Yea I just tried down loading a few pics and it failed. I did add oil to the cyls and compression did not rise so I assumed bad valves. I was expecting to see a burnt valve, crack, something obvious. I am letting it sit upside down overnight with the tops of the valves submerged in trany fluid to see if it leaks by. Same with the worst cyl, # 3 which has the piston down. I filled the cyl up to the top with trany fluid. In the am I will see which leaked by, the head or rings.

93toyrunner

I had the same problem last summer I do not remember which two cyliners I think it was 2 and 3 I had a shop clean it and do a suction test even though i knew the two were bad from compression test they replaced all the valves at $10 a piece grinded the old seats clean for free then $50 to resurface head so i was pleased with new exhaust valves clean heads all for $110 nice cheap fix

93toyrunner

My valves were the same though mostly whitish then the two bad were black and oily your cat might be bad two from all the unbuned fuel going through it so I would check it or even replace it

CaptJohn

OK, I'm a little more encouraged now. So you guys did not have obvious cracks or burnt/tuliped valves? On mine, the 2 cylinders that had the low compression, both intake and exh valves were oily. The other (4) good cylinders, the exh valves are diffinetly white in color, no oil at all..

93toyrunner

the intake valves were fine on mine once they cleaned the head i still could not ell the valves were bad on actually passed the suction test but i said it had low compression so he moved the valve up and down a couple times then tried it again and it failed the test so i said replace them all and he cleaned the seats for free because the valves had to be ordered and it was delayed twice so the whole job took them two weeks when it should have taken three days so i got a good deal

CaptJohn

Thanks for your help....did you notice much increase in power...I hear nothing but grief about these 3.0 engines but they are everywhere... Most people have high miles on them too...

93toyrunner

I baught it like that running on 4cyl and i could barely maintain 70 on highway with 31's so i loved the power increase but the 3.0 is still a slower engine but i do not mind it too much because if it had more power i would break more

CaptJohn

OK, nice talking with you. I put in a post when I get the heads back from the shop, see what they say...