1990 K1500.... Is It Dead?

[kdawgg35115]

I have a 90 k1500.It is 4x4. 5.7 engine. brand new transmission... only paid 900 dollars..... on to the problem.... smokes on startup and if it idles for a period of time.... sounds like valve guide seals to me, but there is another problem. I pulled a pontoon boat the other day and it ran pretty hot and just didnt like the extra load at all.... any other time it runs great and has plenty of power. I can hear a sound if i get on it a little bit, sounds like valve rattle... the truck has 350,000 miles, but runs great any time except when i pulled that load. any help would be really gret.

[[email protected]]

I have a 90 k1500.It is 4x4. 5.7 engine. brand new transmission... only paid 900 dollars..... on to the problem.... smokes on startup and if it idles for a period of time.... sounds like valve guide seals to me, but there is another problem. I pulled a pontoon boat the other day and it ran pretty hot and just didnt like the extra load at all.... any other time it runs great and has plenty of power. I can hear a sound if i get on it a little bit, sounds like valve rattle... the truck has 350,000 miles, but runs great any time except when i pulled that load. any help would be really gret.

 

With 350,000 miles on it, that engine is not worth fixing. However, 350 sbc engines are plentiful and are found everywhere, so getting a cheap replacement won't be a problem. Since, it's got a brand new tranny, I'd replace the engine and that truck should run a good while longer.

[kdawgg35115]

I have a 90 k1500.It is 4x4. 5.7 engine. brand new transmission... only paid 900 dollars..... on to the problem.... smokes on startup and if it idles for a period of time.... sounds like valve guide seals to me, but there is another problem. I pulled a pontoon boat the other day and it ran pretty hot and just didnt like the extra load at all.... any other time it runs great and has plenty of power. I can hear a sound if i get on it a little bit, sounds like valve rattle... the truck has 350,000 miles, but runs great any time except when i pulled that load. any help would be really gret.

 

With 350,000 miles on it, that engine is not worth fixing. However, 350 sbc engines are plentiful and are found everywhere, so getting a cheap replacement won't be a problem. Since, it's got a brand new tranny, I'd replace the engine and that truck should run a good while longer.

 

 

any chance it just needs the heads reworked? since it runs so good any other time? also kind of on a budget

[[email protected]]

I have a 90 k1500.It is 4x4. 5.7 engine. brand new transmission... only paid 900 dollars..... on to the problem.... smokes on startup and if it idles for a period of time.... sounds like valve guide seals to me, but there is another problem. I pulled a pontoon boat the other day and it ran pretty hot and just didnt like the extra load at all.... any other time it runs great and has plenty of power. I can hear a sound if i get on it a little bit, sounds like valve rattle... the truck has 350,000 miles, but runs great any time except when i pulled that load. any help would be really gret.

 

With 350,000 miles on it, that engine is not worth fixing. However, 350 sbc engines are plentiful and are found everywhere, so getting a cheap replacement won't be a problem. Since, it's got a brand new tranny, I'd replace the engine and that truck should run a good while longer.

 

 

any chance it just needs the heads reworked? since it runs so good any other time? also kind of on a budget

 

 

It's possible, but the rings may also be worn letting it burn oil. I would just replace the engine, used 350 sbc are dirt cheap in a junkyard somewhere. Getting the heads worked will cost almost as much as you can get a used 350 engine for. The other week, I just got a 350 vortec out of a wrecked 97 chevy for 100 dollars, so they're out there.

[Patrick H]

Exhaust smoke is indicative of valve stem seals..

 

As far as the motor, I'd start with a compression test.

[wierdo124]

You can't kill a 350, and if you manage to, they're everywhere, thusly dirt cheap.