alright guys this is a weird one, im looking at this 92 4runner, 3.0 v6 5spd 4x4, this thing is clean, almost no mud in the engine bay, hardly any rust (rear bumper) and he only wants 1500 for it with new tires, did a compression test today, 145 accross the board, except on the back right...... 120.. but its runs great? has plenty of power, even for the 3."slow" and can burn the new 33s in second gear, i kid you not this thing is plenty fast, but im worried about the 120 psi test, whats it say? HG about to blow? 250k on it but new motor with 130k on it, its was the toyota recall, they put a 2nd gen 3.0 in it by what hes telling me, im just confused, never had a low compression with a motor that runs great and can spin oversized tires in 2nd, ideas guys? its got new tires, hes in a jam and needs 1500 quick so gimme ideas!!!!!!

 

that 120 cylinder should be fine, I would say low is around 100 or lower. If a head gasket was goin' you should see a much higher comp somewhere in the test. If it was goin, they tend to leak into the cylinder and allow less air to pass around the rings, which would increase the comp.

Or you can always do like I do and check for a white smoke when ya run it.

my 2 cents...

 

it doesnt smoke or anything, im just amazed of how well it runs, got plenty of power and everything

 

any ideas guys?

 

Could be a burnt valve or they need adjusting (its a semi-big job).

Make sure the cooling system is up to par and you should be all set HG wise.

Sounds like a good truck though..

 

HG won't cause low compression. It's either valve issues or rings.