Compression question need you guys help

[75steelers]

I have a 292 inline 6 the #1 cylinger has 130 the #2 130 #3 60 #4 130
#5 130 and the #6 has nothing at all it fires and it cranks just fine but it does'nt have alot of power. can anyone tell me what might the problem be thanks for your responses

[Jeepster376]

#3 has a problem for sure, and it's difficult to tell exacly from the compression test. But odds are either a colapsed or cracked compression ring, or a leaking, bent or burnt valve. One test to try now is dropping a teaspoon of oil in the cylinder and take compresion reading again. If the reading is higher with the oil, it would more than likely be the rings. A head gasket is unlikely, normally you would find a low reading on two adjacent cylinders, if it were a blown gasket. Performing a leakdown test would help further determine just where it's leaking. But one way or another if you intend on fixing it, the head needs to be removed.

[smitty62]

Sounds like the rings are worn out-do you know how many miles are on it? #3 & 6 cylinders are just coasting--but hey!--- Cadillac is building new engines that do the same thing!!

[Jeepster376]

Oh jeez, I didn't see that #6 has nothing. That's not good.

[75steelers]

Should I just replace the motor or is this motor worth rebuilding and if it is rebuilding about how much do you think the parts would cost

[Jeepster376]

If the problems are in the head, a valve job could get you going again. If the problem is pistons or rings, then it's a tougher call. Depending on what you wanna put into it, and the condition of what you find inside, you could get away with a hone and ring job for a couple hundred, on up to boreing and rebuild completely for a lot more. Wether or not you need machine work done on the block crank and head makes a big difference in what it will cost. It's not realy possible to estimate without dissasembling and measuring the condition of what you have.

[smitty62]

If the problem was valves it would miss and he would notice it. The man said it runs ok but no power. With a 4 cylinder I suspect he's right I would think it uses quite a bit of oil as well.
I can tell you from experience that completely rebuilding a six is VERY expensive. I had $1500 in PARTS & MACHINE WORK ONLY--no labor-- in the last one a year ago --never again!

[Jeepster376]

Valves rings or whatever, with no compression in #6 that thing is missing, and #3 probably isn't firing either. I don't know the firing order of the six off the top of my head but if 3 and 6 are spaced right it may be running somewhat smooth on four cylinders.

10-4 on the $1500 parts and machine to do a rebuild. ~$2000 fully assembled.

I don't know if I would recommend this, but I had a 300-6 in an F-150 (can I say that here?) that dropped a cylinder. After doing compression and leakdown tests, I determined it was a ring problem. So not wanting to fix what wasn't broke, I pulled the head and pan and popped out the pistons. I found my cracked ring, but also found several of the pistons were cracking in the skirts. So I got a set of pistons, rings, rod bearings, and gaskets. I honed the cylinders in the truck, put it back together and was running on all 6 again for about $300 and an afternoons work. It wasn't a new engine of course, but it ran good enough for a couple more years, till I finally got rid of the truck.

[75steelers]

thanks for the info guys I think I might just put a 350 in it or i may just sell the truck. if you know anybody that is interested in buying it