Airstream w/ 454 Power & idle problems

Re: Airstream w/ 454 Power & idle problems


My neighbor FINALLY did a compression check, but only on cyl 5 & 7. He said he got 185psi on #5 and 0 (zero) on #7.

I pulled the valve cover off to check out the knock and investigate the pressure loss. I found that there was a rocker arm off, so the knock was the push rod hitting the cover. There doesn't appear to be anything damaged, just loose. I have a mechanic coming over Sunday morning to check it out further and put things back together. I hope this is the source of my problems!
Re: Airstream w/ 454 Power & idle problems

My mechanic was unable to stay - he looked at the problem and said the setup would allow me to do it, and instructed me on exactally what to do. The rod was very slightly curved at the end, so I replaced it with a new one.

Here is the new problem - When I put the rocker back on top of everything and tightened it up as much as I could, the rocker can still be wiggled along with the rod. I started the engine and let it idle for about 30 seconds and check under the valve cover again. I still could not tighten it anymore, and the rocker was still a little loose.

Any ideas?

C Nash

Senior Member
Re: Airstream w/ 454 Power & idle problems

Was it still knocking? Check the height of the rocker stud. I think those screwed in but some were pressed in the head. With the engine running back off the rocker nut until the lifter rattles. Slowly tighten one turn from no lash. It's possible the lifter has colasped or came apart. Ck to be sure solid lifters have not been installed. Might have a hot rod engine :eek: Might need to wait for the mechanic
Re: Airstream w/ 454 Power & idle problems

No, the knocking is gone, and it seems to run much smoother! The rocker bold screws in. I have it as tight as I can get it, and the rocker is tight and doesn't move. The strange thing, is that I can move the rod up and down - very slightly, however it does move a little.

I don't really know what I'm talking about, but i think your idea about the lifter being colasped seems like a logical reason the rod is not tight/secure.
Re: Airstream w/ 454 Power & idle problems

I took it for a test drive and it drove great - for about 4 miles. The engine gives a little octane ping noise (despite it was filled up with Unleaded-Plus). On the way back home, after a good warmup, the performance decreased. I could get up to 30mph top speed, however it took awhile. The engine would just bog down if I tried to give it more gas.

Because of the other problems that I had, and the fact it decreases performance when it gets hot, what about the cat converter? I don't want to wait around until dark to see if it gets red hot. does anyone know what tempature it should be so I can check it with my laser temp toy.
Re: Airstream w/ 454 Power & idle problems

Disregard the catalytic convert idea. I took it to a muffler shop and they opened up a hole just before the cat. She runs the same as before, only I have exhaust fumes in the unit now. :(

I drove it about 20 miles through normal traffic and redlights. It sounds good, however has no power and gets to 15mph very, very slowly. It seems to get a little surge of power between 15-20mph, then will loose power and no matter if I floorboard it, or slightly give it gas, it will very slowly increase to a top speed of about 40mph. I can go a little above 40 on a straight-away, however the engine starts pinging like a lack of octaine sound.

I have fixed everything possible from my driveway. I guess I have bigger problems. Any last resort ideas before I take it to the big truck shop and take out a 2nd mortgage?

C Nash

Senior Member
Re: Airstream w/ 454 Power & idle problems

TG, have you got anyone to ck the computer for codes yet? If the check engine light is coming on this is the frist thing to do
Re: Airstream w/ 454 Power & idle problems

I'm going to take it to a mechanic shop tomorrow when I get home from work & have them check the codes. The check engine light has only come one once, and that was right after it backfired a few times after the tune up. The light went back off as soon as the engine smoothed out.

I had another mechanic friend come over and take a look today & told him my story. He is suspecting a stuck lifter and/or the engine needing a valve job. He is concerned with that rod that is not completely tight, and suggested another compression test to see if I still have a dead cyl.

I have come to grips with dropping whatever money is necessary and having someone else (aka: a professional), put this thing in perfect working order. I have a 2000 mile vacation coming up in just 6 weeks, and I don't want to take my wife and 3 little girls across the country in something I have tinkered with for weeks and doesn't carry my full trust.

Of course, I still pray that someone will post that quick fix answer that takes me 5 minutes to fix and cures all my problems... Anyone got that answer???
Re: Airstream w/ 454 Power & idle problems

Another friend of mine came over tonight and brought his $6000 reader. He is a young mechanic working at a major shop here in Houston, and my other friends that are "old time" mechaincs call him the new "mr gadget" mechanic. There were no codes in the history, however he printed out some charts and graphs and read the screen while I drove around. I was very impressed with his little machine. It told him that the engine is missing alot & passing too much raw fuel. It also read high temps in the manifold/exhaust, fuel mixture too rich, and a few other things I can't remember.

He said he needs to bring some more electrionc toys over tomorrow and described something that will tell him about the timing, spark, etc, that clips onto all the plug wires. He was very reassuring and said he things the problem is a combination of electrical issues and fuel delivery.

He also said my fuel injectors have a poor pattern and need to be professionally cleaned, however did not feel that had anything to do with the problems at hand.

OK, I'm starting to see a possible light at the end of the tunnel without having to shake the money tree!!! :)

Re: Airstream w/ 454 Power & idle problems

Just a quick update:

We did another compression test . 155 lbs on everything except #7, which was 65lbs, so the head is going to have to come off.

I got my first estimate from a mechanic shop that also does alot of RVs - $2600 if I do both sides. They also said to expect to pay $400-600 more for "breakage" because they expect for things to go wrong and bolt heads to break off and need to be drilled.

Does anyone else think this is a little high?
Re: Airstream w/ 454 Power & idle problems


I took it somewhere else (not the expensive place above) who said they would only charge about $1500 for a head job on both sides. They called me back today and said to come pick it up, they have healed it.

Turns out it was a stuck lifter. They disassembled everything under the valve cover and did a good inspection, and freed the roller lifter on #7. Compression when they were done is 140 lbs on all 8. They also had to pressure clean the fuel injectors, which were slightly clogged. Turns out when they used their very sensitive equipment, they did detect a very slight restriction causing a slight blackflow in the cat. This was taken care of as well. Final price (before the transmission service I added) was $775 out the door.