V6 problem

[futar]

A female friend just purchased a 1989 Sunrader V6 with 67,000 miles. She felt that the engine was running rough so she took it to a reliable mechanic. He found that #3 cylinder pressure was low at 50#s. I had previously checked the VIN and it was not part of the head gasket recall.

The oil and radiator fluid is okay which I use as a sign of a head gasket failure. The exhaust is clean. I am thinking of all we can do to determine the problem. The vehicle sat for a good while so I'm wondering if a motor flush in case of a sticky valve would be in order. I am also wondering if someone did a bad job of adjusting the valve lash.

Okay gang, here's your chance to rescue a damsel in distress so don't let me down. Try and message me if you can.

[Shoprat]

Hey Futar !

Have the mechanic pressurize the cylinder with compressed air. Listen at the intake manilfold , exhaust pipe, and place your finger over the outlet on the rocker cover for the P.C.V. valve and feel for pressure there. This will probably point out a leakey valve , stuck rings, etc. Then you can go from there.

Hope this helps.

[futar]

Well, I went over to check out the rader. It is in really great shape. It doesn't have a generator but still I can't believe she got it for $8,500. It has new Bridgestone tires which may explain her 12 MPG on her trip back. They're M&S and were only inflated to 35 psi when they're 50 psi tires. I don't like the M&S ones on the road. Also they put 195s on, which I did on my first one years ago.

I started the engine and it ran good and smoothed out when it warmed up. I find that these TMH V6s lope a little like they have a truck cam. The exhaust was clean and no backfires. I listened with my auto stethoscope and couldn't here any tappet noise or mis firing.

She claims that when warmed up on the road, it runs rough when she comes to a stop. I wonder if something in the emissions control system needs replacing. I'll also put in some injector cleaner. I'm borrowing a compression gauge to make sure that they didn't make a mistake. It runs too good for an engine that has one cylinder at 55 psi.

I noticed the rader has the premium air bags in the rear unlike the cheapo badly installed ones on my Winnebagel. My only critique is the chassi mount propane tank. They have a tendency to rot out on the bottom in certain areas and are a killer to find and replace. I noticed a lot of little thoughtful things on the rader like a convex roof so water doesn't pool in the middle.

Let ya know what I find