Dissappointed in the 350

I always heard praises of GM's 350 V-8 while growing up, so when it came time to buy my own truck, I chose one with a good ol' 350 (a.k.a.

5.7L). It's a 1999 GMC, and with only 38K miles, I just had to get a valve job and new valve stems. I changed the oil every 3000 miles and had all scheduled maintenance performed by the dealer. So much for GM's claim of "the most reliable trucks on the road." With new competition from Toyota and Nissan, GM sure seems to be moving backward in the truck market.
Reply to
Ric Bednar
Loading thread data ...

"Ric Bednar" wrote

Your experience is the exception, not the rule with these engines. I've hardly even seen the heads off these engines...especially at that kind of mileage. And I've never seen valve jobs and and/or stem seals replaced at that kind of mileage. So you either got a bad one, or you or someone else is attempting to fix a non-existant problem.

Ian

Reply to
shiden_Kai

I have never heard of those problems at that milage with that engine. Are you sure you did not leave a 2 or 3 off one end of the 38K miles?

Reply to
=?x-user-defined?Q?=AB?= Paul =?x-user-defined?Q?=BB?=

Never seen one need any interior engine work at that mileage. Very strange. I have about 8 of them around here and none of them have less than 100K on them. The one in my van has 110K and still runs great. You may have gotten a Friday truck.

Reply to
Steve W.

Valve Stem Seals at 38K? Not only is that abnormial, that and a "Vavle" job at that milage would lead me to beleave some one put used cylinder heads on it. Newer fast burn or Vortec heads are not known for cracking. I have seen 1 pair that was. Each head from a different truck.

The only 350 heads that had cracking problems were 882 & 641 casting. I have a buddy that has 882's on a 12.5 to 1 compression ratio 350. He's put

50K on the engine since slaping it togher from parts laying around the junk yard. His problem is, he never cleaned the rust off of the vavles, and one has started to seize up when the truck sits longer then 3 months.

What cracks 350 heads, or any small block chevy heads, is being run while exceeding 260 degrees of cooliant tempiture. If you did that to your truck, and GM warenteed it, consider your self lucky. Warentees do not cover abuse. Charles

Reply to
Charles Bendig

I have a 1999 K1500 with 56,000 miles on it. Oil changed at 3 to 4 thousand miles, runs like new and uses no oil. Smooth idle, smooth power. Mine is the normal for a 5.7 liter Chevy. And has never been apart.

Brian

Reply to
NoSpam

No, not valve SEALS - valve STEMS. He got new valve STEMS. Right after that they changed the bumper fluid.

~KJ/TLGM

Reply to
KJ

A chev 350 is generally tired at 200K+ A nissan titian would be lucky to make it to 100K The japs make good cars but they don't have the redneck in 'em to make a decent truck.

~KJ/TLGM

1990 GMC FS Jimmy 350CUI TBI w/ 114K & only oil changes.
Reply to
KJ

Interesting that you would want to compare a 5-year old truck to the new crop of Nissans and Toyotas. Go back to 1999 and see what they used to import and tell me that they had anything even remotely comparable to a ChevyGMC full-sized...

That aside, the repairs you experienced are quite abnormal for that motor. In fact, I would have a hard time believing that even an severely abused 350 would need a valve job before 40k miles. Methinks someone is pulling the wool over your eyes.

Just exactly what symptoms were you experiencing that made your mechanic say out of the blue "Oh yeah, you're gonna need a valve job."?

Cheers - Jonathan

Reply to
Jonathan Race

I beg to differ ... Toyota has made excellent trucks for 20 years at least.

Reply to
Celica Dude

maybe If you woulda went backwards In years you woulda been ok.I have always had great luck with older 1970 up stuff.

Reply to
TONY 70000

Yall should go to Japan and see how the vehicle industry there is. Cars after 3 or 4 years are worth practically nothing. Government regulation, emissions testing and safety make it impossible to keep an older car unless you have alot of $ to keep it on the road. It's not unusual to see a 4 year old car for sale like 10000yen (about $100). If there is rust or a dent, you need to fix it before passing. The emissions testing is something like 0 the first year, you pay 25% the next year (about $1000) then 50% 3rd year ($2000) then

75% then 100% on out. These are done EVERY year.
Reply to
®

Response to the many replies:

The GMC dealer did the work after several month of troubleshooting. At first, they thought the cause was the fuel injectors, so after 5 fuel injector flushes and continuing problems, they determined the valve guides needed to be drilled out and new valves put in. The dealer also said this actually is becomming more and more common for late model 5.7L engines. They've seen a significant increase in valve jobs, regardless of mileage. Unfotunately, mine was just one year out of warranty, even though I have very low mileage (38K is the correct odometer reading). The valve job fixed the problem, the engine is running great again, so it's safe to say this was the root cause.

I like Tony 70000's suggestion: stick with the earlier model trucks (~

1970 :-) )

Ric Bednar wrote:

Reply to
Ric Bednar

Reply to
seeray

The service engine code kept coming on and referencing stuck injectors. After 5 trips to the dealer to flush the injectors, the problem continued. The service crew had run into this before -- for some reason, when the valves get gummed up and stick, the engine mgmt code that comes up points to the injectors. I guess it was only through experience of having been there before and witnessing the same symptoms again that lead to them to the valves.

seeray wrote:

Reply to
Ric Bednar

But if the valves and guides were just carboned up, and the compression was good and didn't leak down they could have at least attempted to run GM's top engine cleaner through the motor. I've used it in the past and it works wonders on gummed up motors.

Brian

Reply to
NoSpam

Three words: You Got Taken.

Reply to
=?x-user-defined?Q?=AB?= Paul =?x-user-defined?Q?=BB?=

..something else sets off my B.S. Meter... the 99 trucks no longer offered a 5.7L. 4.8 or 5.3L GenIII V8s, no more "classic" SBC. (or a 6L in a 3/4 ton)

(unless it's a Yukon or something - I believe those used the old engines for a bit longer, but the new series trucks swapped engine types at the redesign...)

Ray

Reply to
Ray

there was some stuff we had sitting around the shop called 22K or 44K or something like that... supposedly worked like a champ, but the cans were old, so i didn't want to try it.

Reply to
Celica Dude

you could buy a c/k up until '00 as a C/K Classic w/ a 4.3, 305, or a

350. they were sold right along side the Silverado/Sierra's in '99 and '00.

-Bret

Reply to
Bret Chase

MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.