3.2 leakdown advice

[larrym]

need an armchair diagnosis

before I start tearing it down, what are your tho'ts on what i might expect to find in there?

I have a spare '88 3.2 that i recently leakdown tested for a potential buyer; cyls 1-2-4-6 are all 2-3%, but 3 & 5 are really bad 35-45% leakage - can sort-of hear leakage thru the exhaust system which is still all intact

why 3 & 5 ???? - any experienced thot's ???

#5 intake adjustment was almost 0 & exh was excessively loose - (I have not checked #3 yet cuz it is a pain to get the cover off with the CAT in place and sitting on a pallet)

It came out of a reportedly "good running" (when wrecked) car, said both the P.O. & his shop

I don't need this engine - so spending bunch of $$ and TIME to TOH it might not be on my priority list; i may just part it out instead, but having some idea about what to expect inside will be a factor in the decision

your thot's ???

[Steve@Rennsport]

What % did you see on the gauge with # 3 & 5?

Might be bent or burnt valves, but you'd have to look inside there to see the latter.

[larrym]

mea culpa, yes - "please provide ALL the details" !

35-45% leakage on 3 & 5 - bent valves - maybe

? - could that happen if the driver was accelerating upshifting when t-boned by a Volvo & maybe floored the throttle in neutral in the melee?

I didn't think we could get valve contact in a street 3.2

a bent valve could account for the excessive adjuster clearance now that i think on it - guess I'll go pull the other cover & check #3

thanks!

[E Sully]

There is a rev limit in the DME, more likely a down shift to over rev and bend valves.

[Jcslocum]

I'm thinking that you will find bad valve guides and worn valve seats and or valves. The 3.2 is known for bad guides, particularly the exhaust. It essentially needs a valve job to make it right. If you do the work and there is no other big surprises, maybe cost will be $2k...

[Walt Fricke]

Agreeing with Steve is always a safe bet. Perhaps the rod bearings on 3 and 5 were a bit more worn than the other four, and a mechanical overrev (downshifted into too low a gear) caused those valves to hit the cylinder when the others didn't. If the lash was tighter for them, that might contribute. I don't know if there is a relationship between worn guides and dynamic valve to piston clearance, but I imagine that can't help if the wear is to the point that the valve can descend on a slightly different axis, which will tilt one edge of the valve downward from what it is designed for.

The 3.2 rod bolts aren't as strong as their predecessors because they are a millimeter thinner. Perhaps the bolts on those two cylinders stretched a bit.

Since you bought this motor, does any of this make a difference? You said you were going to take it apart anyway, and you'll soon see what's what.

Me, I'd use my borescope through a spark plug hole to take a look at the top of the piston for signs of contact. And I'd try to see how the exhausts look when they are supposed to be closed, though that might be equivocal. Your leakdown pointed to bad exhausts. You know the cure for them. When you get the exhaust off you can check to see if the valve guide boss part of the head is cracked.

[Steve@Rennsport]

Originally Posted by larrym

I didn't think we could get valve contact in a street 3.2

OMG, yessss. Its VERY easy with a missed shift.