heating problem on 89' v3500

[1967k10]

We've got an 89' V3500 4x4 work truck that's heating on us. A couple years ago we had a new motor [350] and tranny [th400] put in. After it was installed it started heating .We took it to the place that built the motor and trans and they put a new radiator in. It continued to heat so they put another new radiator and new temp guage in. It still heated so we just drove it in winter. Now we need it all the time and need to know what's the problem. I'm thinking about putting a 3 or 4 core radiator [it currently has a 2 core] but that doesn't seem like it's the real problem. could something have gotten left in the motor? a rag or piece of plactic? We need some answers. Thanks

 

[73k5blazer]

A regular ole 350 shouldn't require a 4 core rad, but it can't hurt.
How about the old t-stat? I've had lots of bum ones brand new from the store. I always test mine now on the stovetop in a pot of boiling water and a meat thermometer to ensure it opens at the proper temp. (My wife loves me)
Doubtful that there's something blocking up the internals.
Could be a bum water pump too.
How quickly will it overheat?

I'd put my money on the thermostat.

 

[goldwing2000]

I's agree with t-stat or water pump.

Did the fan shroud go back on wfter the engine swap? That'll make a difference.

 

[1967k10]

Yeah the fan shroud is on. I wondering about the t-stat. A new one would be a cheap fix.

 

[DPI]

Yeah the fan shroud is on. I wondering about the t-stat. A new one would be a cheap fix.

Make sure you get the correct T-Stat. Don't try a lower temperature one. I was told by a machinist buddy of mine a lower temp may actually make it run hotter since it will open up and not let the radiator do its job.

Also, make sure you don't have a intake gasket leak. I had a 350 with a warped aluminum intake that made it run at 210 degrees all the time and this was a carbed motor.

Use a spray bottle with water and spray around the edge of the intake while the motor is idling. If it idles up, then you have a leak somewhere. You can also use wd-40, but it is flammable... So be careful

 

[cjjones]

Check your catalatic convertors, I have a 01 with the 5.3, constant heating problems when put to work, after alot of wasted money, discovered the cats were blocked, cut them out and havn't had a problem since.

 

[1967k10]

That's the first mod' our trucks get when we get them.I hate catatlitic converters. I wonder what the correct t-stat would be for that truck?

 

[1985_K5_Silverado]

That's the first mod' our trucks get when we get them.I hate catalytic converters.

No kidding; when you don't even have smog tests, chop those things out and sell them on ebay. Same with the air pump, EGR, etc.

I run a 195 deg t-stat, and 205 is about as hot as the gauge gets with a healthy 350 and a heavy right foot in slow, stop-n-go traffic (cooling system is in excellent shape, with factory HD rad, full shroud, and clutch fan).

 

[73k5blazer]

I hate catatlitic converters.

Hate them you might, but they are responsible for the single largest improvment in our air quality, ever. The ones today aren't even restrictive and hardly weigh anything. The ones from the late 70's and 80's kinda sucked, prone to blockage, weighed 75lbs, only worked for 80k mi. If you think LA is bad today, go back to 1975, when you could hardly breathe outside. TOady there's twice as many cars and half the pollution.
ANd no, I'm not a liberal.

 

[4xcrazy]

Hope it has the correct waterpump installed in it, as i mentioned in another post, those water pumps are reverse rotation, still going to get some kind of flow, but not what you'd need for proper cooling.

 

[HarryH3]

Running too lean can also cause overheating problems.

 

[1967k10]

Hate them you might, but they are responsible for the single largest improvment in our air quality, ever. The ones today aren't even restrictive and hardly weigh anything. The ones from the late 70's and 80's kinda sucked, prone to blockage, weighed 75lbs, only worked for 80k mi. If you think LA is bad today, go back to 1975, when you could hardly breathe outside. TOady there's twice as many cars and half the pollution.
ANd no, I'm not a liberal.

I'm sure you are right but I live 40miles from the nearest town and don't much care for big towns.

 

[goldwing2000]

That's the first mod' our trucks get when we get them.I hate catatlitic converters. I wonder what the correct t-stat would be for that truck?

Definitely a 195. I don't think a car has rolled off the line with anything lower than a 195 for at least 30 years.

Every parts store's lookup should tell you what factory replacement temp is.

 

[dyeager535]

Is it overheating no matter how the truck is being used, only at idle, only on the freeway, etc.?

 

[1967k10]

It's never driven on the highway.It's a Ranch truck with a bale handler on it. We use it to feed our cattle and go to the field. It does it mainly when it's driven really slow or in a soft field. The thing is it's never worked that hard,it doesn't pull a trailer and it is usurally only hauling 1500lbs.

 

[HarryH3]

Make sure that the fan clutch is engaging. If it isn't, then the radiator just won't get enough airflow at low speeds.