Heating issue

[Dvldog8793]

Howdy
Looking for an opinion....My blazer has some heating issues in the winter. I run a 195 shaw stat. This blazer has a huge radiator and no A/C. Even in the summer it never gets to 185 degrees and most of the time runs in the 170-175. In winter it struggles to get to 165 and then if I turn the heat on High it drops the temp to 155-160. I have the radiator blocked and still only runs in the 170 range and does not put out enough heat for the cab to warm up.

Question....What temp does the 6.2 like to run at for best efficiency?

Opinion....Would removing the fan and installing an electric be an effective option? I am not a big fan of electric fans but in this case I think it would work....?

Thanks!

[joeq]

Most people complain about overheating of their vehicles. This is the 1st time I've heard it on the opposite end of the spectrum. I can understand the diesels do run cooler than their gas counterparts, but never heard of it on the negatives. If you're cab isn't warming up, could the heater core be blocked, or the heater box door not operating correctly?

[Dvldog8793]

New core, new radiator, new stat, fresh system clean out, all the parts of the heater system work great except the temp. This engine runs so cool that I have to disconnect the fresh air induction cause it lowers the op temp 7-20 degrees when cruising....
This all considering an ambient air temp of -20-30 degreesF

[DmaxMaverick]

Retarded timing? Hows the rattle, power, cold start and smoke?

You might try a non-OEM style (cheap, not a R/S) thermostat with the highest rating you can get for the winter. They're typically more restrictive, and NOT recommended for summer or heavy loads. You can also put a pop rivet in the bypass hole(s) in the stat, and make sure it's installed correctly (typically causes overheating, but....). Other than directing the intake inlet to the engine compartment and blocking the radiator, there's not much more you can do.

[Dvldog8793]

Hadn't thought of the timing issue....or using the more restrictive stat...
Thanks Dmax...

[AKMark]

On the K-5 in my signature, I have dual electric fans from a Plymouth Breeze. I don't turn them on until it gets up to 190, and if it goes much over 200, I put them on Hi (they have two speeds) and haven't had problems with heat or cool issues.

Now up here in Alaska most diesels struggle to produce heat even with very warm thermostats.

My 82 has no issue as I believe the plow diverts all air around the radiator, and it runs at 200-210 consistently and will burn us out even when the temps drop.

I've had several 6.2's up here, all were a bit different on what I needed to do to get them warmed up. A few of my Suburbans had issues giving enough heat for a rear heater and a front one. They could do one or the other, but not both.

[Dvldog8793]

Howdy
Given that I never pull any real trailers with this rig....I am leaning towards removing the fan and going with electrics. I am also going to check the timing and see if that could be an issue.

A side note about your AK's plow truck....The plow in front creates a negative pressure zone in front of the radiator and will pull warm air from the engine bay through the radiator. I would bet that if you put a grill cover on your truck would run cooler if you wanted.

Thanks everyone!

[john8662]

Possible your diverter door isn't working in the HVAC box and your gauge isn't right?

Take an infrared heat gun and shoot the water crossover when up to operating temp and see how the numbers compare.

I know for a fact that the bottom number on the coolant gauge isn't the right number. The first main line is around 180.

J

[joeq]

As far as timing goes, on a gas eng., a retarded ignition makes the eng. heat up. Would that also be the case when retarding the fuel timing on a diesel?

[DmaxMaverick]

As far as timing goes, on a gas eng., a retarded ignition makes the eng. heat up. Would that also be the case when retarding the fuel timing on a diesel?

Nope. Just the opposite. The injection is the ignition event. If it's late, you get an incomplete burn at a lower compression. The result is more smoke, less power, and decreased cylinder temperatures. A poor injector spray pattern can cause the same thing.

Also, comparing Diesels to gassers, Diesel has a more broad BTU (or KW) output, both at the crankshaft and heat generation. A Diesel, generally, generates less heat at lower loads, and greater heat at higher loads. The problem we often see is, a cooling system capable of managing full load heat will be major overkill at lower power demands. A result of this is a typical difficulty to maintain engine heat in very cold climates during light loading. Heaters that don't heat. It's a delicate balance, and we often see both ends of the spectrum discussed here. A heater core is nothing more than a radiator, that captures the rejected heat to warm the passenger compartment. Whatever heat above ambient that is at the vents is heat removed from the cooling system.

[AKMark]

I don't want it to run cooler. When I'm plowing snow at -40 I like it when the heater works great.

It has yet to go over 210, so I'm not worried. If it does, then I may reconsider.

[joeq]

If blocking the radiator doesn't warm the eng. enuff, then I agree with Dmax. Put in a restrictor insted of the original thermostat, and keep the water from going through the radiator.