Trip to Seattle killed my truck...

[kiley]

Well almost. My wife and I made a trip to Seattle from Salem, Or yesterday and today. I pulled a uhaul trailer up there and back. On the way up I noticed a little knocking/pinging. Don't really know the difference between knocking and pingin but I know what it sounds like when it happens.

I have been adjusting my timing and air/fuel ratio the last few weeks. We picked up a load from IKEA and headed home. With the heavier load the pinging was worse. Seemed to happen at around 1500-2500 rpms, especially just before the secondaries kicked in. Also was bad a full throttle. I made a few adjustments along the way and I just got worse and worse. I pulled into
Salem and it backfired and died. bearly got it started again. After that it was knocking/pinging so bad I was afraid to drive it anymore. I had to advance the timing to 16 just to get it running again.

I'm not sure what to do? If I time it to 8 it chokes, sputters, backfires and dies. If it's timed around 12-16 it will run but any throttle makes it knock and ping.

What do I do?

BTW I have hei, edelbrock 1406, performer carb and an rv cam. RPMs were running high on the highway because of 4.56 gears, ran about 3000 rpms all the way up and back.

[Blue_71]

first thing i would do is get rid of the edelbrock, then i'd check the adjustment on the valves. mine does that too (the 89) but its because the cam is wore so bad the valves need adjusting

[dinnut]

is it possible your timing chain is going bad and slipped?

[71-longbed]

im guessing timing chain as well .. maybe you jumped a tooth .... did the pinging happen all of a sudden or did it slowly get worse and worse ..... i drove my 350 to oregon city and back today .... other than sucking down 1/2 quart of oil ...no problems

any more info would help us on the diagnosis

peace

[kiley]

The pinging got worse and worse but I attributed it to my tinkering more than anything else. Could be

It's so far out of whack that the timing chain was my guess. I pulled the cap and rotor off. They are a year old but already showing heavy wear. I'm pulling spark plugs tomorrow.

Besides a quart of oil I went through a tanker truck full of gas too

I've never understood how a timing chain could skip a tooth.

[71-longbed]

it could also be your vacuum advacnec canister ..just a thought.... did you time it with a light ??

[kiley]

I did time it with a light, just happend to have one with me. I wondered about the vacuum advance being stuck. I have never tested one before, How do I check it?

[71-longbed]

the only way i know ...is to disconnect the hose from the vacuum advance hose from the carb and simply sucking on the end and seeing if the rod moves while you "apply" suction .... not pretty but it will give you an idea of what its doing ..... i recently installed a crane adjustable vacuum advance ... better than a stock canister ....

[kiley]

I guess one of those "vacuum thingies" that you use to bleed brakes/check the vacuum on your carb would work for that.

What am I looking for to see if the timing chain slipped? Would the chain need to be replaced if it slipped? What's the advantage to going to one of those gear driven setups vs. a new chain?

[Cat Fuzz]

Gear drives are way noisy.

[Brad]

...unless you've got a six-banger! They also make 'quiet' gear drives if you end up having to go that route.

[Blue Beard]

I'm assuming your trip was worth it since you ended up going back.

Should have taken the trailer the first time.

Be sure to let us know what the issue is, it may help someone else out.

[jose]

Sorry to hear about your truck Kiley . It sounds like your timing chain decided to skip on you . If you have to adjust your lifters a bit to often then it sounds like the cam went south . Time to replace cam , lifters and chain .

[Blue_71]

how much noise do the "quiet" gear drives make? if you wind up getting a new timing chain (which sounds like a good possability) get a double roller (that is if you go back with chain instead of gear)

[kiley]

I've got a 350 so any other draw backs to gear driven setup?

The engine was rebuit in late 1999. It has run like a top in the 1 1/2 years I've had it. I've never adjusted the lifters. Don't know how.

Is 3k rpms daily too much for an engine?

[67sss]

how about triing a higher octane gas

[ChevLoRay]

The 1405 can be re-jetted to run richer, if the mixture is too lean. A lean mixture will run hotter, and that could cause some pinging, especially under a load.

However, the idea that it used so much fuel makes me think fuel is flooding the cylinders and thinning the oil. The thinner oil could cause the knocking/pinging sound you hear. Pull the dipstick and smell of the oil. If it smells more like gas, than oil, there might be something to it.

Quite possibly, your distributor could also be trashy. I put an Accel remanufactured HEI in my truck and it is nice. Not too expensive (~$100 at Advance), easy to install, and has a new vacuum advance already installed. If the distributor has not been replaced, you should consider it. If the vacuum advance is not working (as mine was) and you replace it (as I did) you may find that the now-working advance can cause an intermittent problem with the wiring within the distributor (as I found out). In my case, the wiring to the HEI module was old and brittle and would cause the engine to die when I let off of the gas. It would immediately restart, except for the last time it died. That was when I told the lady behind me that I would honk her horn while she tried to start my truck. She didn't think it was funny.

If not, I'd get serious about the cam, chain and lifters. How many miles since it was rebuilt? I replaced my intake, lifters and carb, in '01. I pulled off a 1405, because it ran so rich. I don't believe the lifters were necessarily bad, but the time was right. I didn't replace the timing chain. When I do, I'm gonna replace the cam. However, the RV cam it has is quite satisfactory.

I, too, think a gear-driven cam would be a nice touch, but a double-roller chain (Cloyes, for instance) would be somewhat cheaper and quieter. If you have a gear driven camshaft, the reason to have the geardrive is so people will hear the whine and be impressed. A friend has one in his small block and it sounds nice. His cam is slow to come on, but delivers the groceries when called upon to do so.

[kiley]

Thanks for all the great info. I don't think it was running too hot. The temp guage was running on the cool side. I usually get about 10mpg. I didn't bother to check on this trip.

How do I check to see if it's too rich/lean?

[68 Suburban]

Originally posted by Blue_71
first thing i would do is get rid of the edelbrock

Smoking the horse dung again

[68 Suburban]

I had that happen with a bad points distributer.

Also, not that this is the problem, but when you are towing a load and/or running the gear you are, you might want to go with a set of "colder" plugs.

[kiley]

The vacuum advance is working like a champ so I think that you guys may be right in thinking the timing chain may have jumped a tooth. I just don't understand how that can happen when the chain is tight. I haven't checked it yet...... and may have just answered my own question. duh.

[lukecp]

I had a chain go out once, made a god-awful noise when i tried to crank the truck over, ran like crap too.

I don't know why mine slipped, but it was a cheap stock-style single row chain, proably with alot of miles on it. When we took off the timing cover the slack in the chain could clearly be seen.

You can get a decent double row timing chain for less than $20

[kiley]

Pulled my plugs. A couple are really black. 3-4 are white/chalky. They were accels and were gapped to .050. Cap are rotor were fairly worn even though they are only a year old. Bought a double chain at NAPA. They guy there said that the chain probably slipped a tooth or two. He really seemed to know what he was talking about.

My book is in storage. What's the procedure for installing a new timing chain. I know about removing the water pump and timing chain cover. What do I do once it's off?

[Razor454]

Did you get a double roller chain with multiple key ways? If you did you might want to advance it 4 degrees, gives you better low-end torque. You are going to need to yank all the spark plugs and then pull out your breaker bar to turn the motor over. 1st thing to do is yank off the old crankshaft sprocket and put the new one on (this is were you can advance it or retard it). Then slowly crank over your motor so that cylinder #1(front drivers side) is at TDC, the crank sprocket will have a timing mark on it; this should point up. Next, put on the chain and cam sprocket so that the timing marks are lined up (they should be pointing at each other). After you line them up tighten the cam bolts to 20 ft-lbs and make sure you place loctite on the ends of each. Put everything back on (chain cover, water pump..etc.). Next you will need to adjust the lifters. What kind do you have? Hydraulic, solid or roller? I hope this helps you so far.

[kiley]

thanks razor454. I got the double roller chain with mutliple keyways (Cloyes). I'm glad you said something about the advancing the timing. I wanted to do that but wasn't sure about it.

Supposedly I have roller lifters. I'll find out for sure soon enough.