Chevy Colorado 5-cyl Grenaded

[clinebarger]

Originally Posted By: ArrestMeRedZ

I plan on following that advice on draining the tank, flushing the lines and checking the injectors. As to Honda engines being stouter, I meant they can spin a lot higher, but in this case, yeah, I think they are. With GMs, I've had great luck with the LS, 5.7 Vortex and other V8 small blocks. Not so much with the smaller engines. I would much prefer almost any Honda engine to this 5-cyl or any of the 60 degree V-6s. Personal experience and opinion only.

I'll check out the valve seat once I have the truck back together and have time to pull the head. If that's the problem, I'll ditch the suspicion about the smog shop.


Touche! Even though the Atlas platform isn't that bad, It got a bad rep like the Northstar....And not 100% deserved! But their V8's....Especially the LS series has few rivals as far as "Stoutness" Hot Rod magazine tried to break one with 26 pounds of boost & made 1200 horsepower with a Stock bottom end 4.8L with a bad cylinder HERE

The rev limiter setting for a light weight Honda would be higher than a lower revving GM engine.

In theory, If a Honda has gummed up valve stems, And a piston smacks a valve at high RPM....The engine will be damaged. Wouldn't you agree?

 

[ArrestMeRedZ]

Oh yes, I completely agree. And my theory that the engine was damaged by overreving is much less likely than a stuck valve or damaged valve seat.

 

[dishdude]

You can't compare an engine designed to be in a truck to an engine designed to be in a small FWD car. Apples and oranges.

 

[ArrestMeRedZ]

Finished getting the new engine in last weekend. Drained what turned out to be a full gas tank, flushed the lines and the new engine fired up like a, well, new engine.

Today, I got the old engine up on the workbench, and pulled the valve cover. Rocker arms on intake valves #2,3,6,7, and 8 were off and loose in the oil gallery in the head. The one valve that was shattered is #3 (the forward valve in cylinder #2).

Intake cam is intact, as are the mounts. I did spill some oil (maybe 1/2 a quart.) out of the dipstick tube getting the old engine out, but only drained about 4 quarts out of it. The new one took 6.5 quarts to fill (spec is 6 quarts.). The oil had been changed by a shop before it went to smog, and I suspect they underfilled it. The oil itself looked new.

I'm at a loss about the rockers. The only way I can speculate they came off is the valve timing was way off. I welcome any inputs that may shed some light on what may have happened.

 

[clinebarger]

Check the valve timing, Just align all the Timing marks on the Timing chain/Gears, If the Intake cam is way off, You found the issue.

After that Pull the cylinder head, The bent Intake Valves will most likely correspond with the Followers that fell off

 

[ArrestMeRedZ]

Yes, cam followers, not rockers. I learned something on the Colorado forums after I posted.

I'll check the timing. I don't know if a low oil level and high RPMs could have contributed to the problem.

At the risk of hijacking my own thread, any problems with your power window motors, front brake rotors warping or sun visors on your 2001 Camaro? I would think that 5.3 would be a great engine for the car.

 

[Doog]

Originally Posted By: OVERKILL
http://www.355nation.net/forum/i4-i5-eng...ad-problem.html
http://www.355nation.net/forum/i4-i5-engine-drivetrain/61639-dreaded-bad-cylinder-head.html

Apparently they have a cylinder head problem.


+2 dude your kid had a bad cylinder head. He lost the GM lottery. I lost the Toyota piston lottery on my 2008 RAV4 which is starting to consume oil because the oil return holes in the pistons are too small. Luck of the draw..nothing more nothing less. I would venture to guess that this would happen no matter if they revved the engine or not.

My only recommendation is to pay attention to the TSB's and recalls on your vehicles once a year. Toyota extended my engine warranty to 10 years 150k. GM...I am permanently off their customer list for this kind of thing. I recommend your son do the same.