engine running hot

[Blue4x4]

I only have 2 hours on the motor. The indicator on the temp stock gauge is passed the "H". Here are a few spec's on what I have observed: I was having lots of problems tuning the engine so I rebuilt the card as it was "schlacked up"(spelling). I had this running hot problem before I took it to paint, but was fixed by drilling a small hole on the side of the t-stat. Now that the outside temp is warmer it is doing it again. I changed the stat and verified it working by sticking it in hot water. The engine is a rebuild, new water pump and cleaned 3 core rad. I took the exhaust temp at the headders just for s#it's and giggles and here what I found:all cylinders running around 210-230 degrees except #2 at 163 degrees and # 3 at 305 degrees. would this be related or just a problems with the valves out of adjustment? Any help is most appriciated. Thanks

[tomatocity]

-Is this an AC truck?
-Make sure you do not have air trapped in your block cooling system.
-What thermostat are you running?
-Do you have a fan shroud? If so where is the fan blade in relation to the shroud opening?
-Do you have a clutch fan?
-Have you checked to see if the lower radiator hose is collasping?
-You shouldn't have to drill a hole in your thermostat. This is an indicator something is not correct.
-I have to ask this. What side of your thermostat is in the intake manifold?
-What is your timing set at?
-Pull the all spark plugs and check 2 and 3 to the others.
-Again make sure you don't have air trapped in your block cooling system.

[Blue4x4]

not a a truck.t-stat 175.fan shroud with the blade just inside the shroud. no clutch.lower rad ok. no hole in this t-stat.t-stat arrow pointing to the rad. Not sure on the timing. found one plug wrong, and some misses gapped.How do you purge the Block????

[cdowns]

are you using a 50/50 mix of antifreeze?

[jhwkns]

With only a couple hours on the engine it'll run warm due to friction. This could be part of your problem. You stated that the carb was pretty dirty. If there's something blocking your fuel delivery causing the engine to run lean could also contribute. What did the plugs look like? How's your radiator? When I swapped out a stock 283 for a potent 350 although I never had any problems before my old radiator wouldn't come close to cooling the larger high performance engine. A new four row, and the biggest clutch fan I could find that would fit in the stock shroud solved the problem. We've had record setting heat for the last couple weeks here in LV. It's a torture test for any cooling system. G/L

[tomatocity]

Originally Posted by Blue4x4

How do you purge the Block????

I have heard of it though I have never seen it in person. I did see it on one of the TV custom car shows but they were not specific to how it worked. They seemed to have a vacuum pump attached to the radiator fill. They had to do it twice to get all the air out.

Agree with the new engine friction, 50/50 mix, lean condition, clean cooling system.
-change your fuel filters.
-make sure your coolant is 50/50. Too high of a % can be not good.
-can't hurt to run some Flush or Cleaner through the cooling system.
-add a back flush T and use it. This can help remove air from the block. After the flush, run the engine with the T uncapped, raise the T above the heads. If you see air bubbles you are removing air.
-check your timing and set it to the stock setting.
-use a 180-185 thermostat. The coolant is cooled in the radiator so the longer the coolant is in the radiator the better chance there is for cooling.
-get a fan with a clutch. It is easier on the engine. Your fan and shroud sound like they are setup correctly.

Taking nothing from LV but Reno and Sacramento are also experiencing record heat. Though I am glad I am not in LV or Reno. Less than two weeks for HAN.

[jimbeau]

Just my 2 cents but here goes.

jhwkns is right ... new motor will run hot especially if running lean.

#2 and #3 running at different temps sounds like valves that need adjustment.

If you have an air pocket in the block I have always been able to free it up with a garden hose inside a radiator hose (going into the block) ,on high, using my hands to seal the two. Make sure that the water has an escape route and be prepared to get wet. Sometimes I have had to do it twice but it has always worked for me.

If you had this problem prior to the new engine then I would also have the radiator checked/ replaced. Sometimes "cleaned" just doesn't cut it and it needs a new or bigger radiator.

Hope it helps.

Jim

[Mad Dog]

As long as the rad. cap is the highest point in the system, you should be able to clear any air pockets by letting the engine idle with the rad. cap off. Remove the cap, start the engine, and let it idle untill the thermostat opens.
Check your timing, run valves.

Just a crazy idea here.....does the engine exibit any other symptoms of overheating? I.E. boiling overflow, alot off overflow, engine feels extremely hot? I wouldn't put a whole lot of faith in a 30 some year old stock temp gauge......

[Blue4x4]

Well after doing a few things it seems to be better. Here is what I did. #2 was a loose plug. #3 was the wrong plug. The gap was too large on all the plugs. I put in a 165 t-stat. It is now running at the last black line before the "H". I am going to get a few miles on it and then work out the issue due to the newness of the enging. Thanks for all your help.

[Fred T]

Check your coolant temp to verify your temp gauge. Best way is to run with the radiator cap loose or the vent upen until the temp gauge is stable. With the engine running, open the cap and insert a meat thermometer.

[walker]

I would definitely check the timing, too much advance will cause overheating. Also the over lean condition will do the same, try backing out the idle mixture screws a half turn or so to see if that helps. I had a lot of overheating trouble with mine before I went back to a stock fan and a fan clutch.

[Radman]

Do like mad dog suggested, it is probably air locked. You mentioned in one off your posts that you checked the exhaust temp, so you must have a infrared temp gun. Check the temp just below the thermostat housing. It should be just slightly hotter than the themostat setting. Then check the hot side of the rad(top rad hose side) then check the other tank. You are looking for a minumin 25 degree drop. If it is less than that then the rad shop didn't do a very good job of cleaning the rad.

do not trust the old stock gauge. plumb in a new mechanical gauge and see what it reads.
ttyl

[cdowns]

another thing that is a common problen is people putting thread sealant and teflon tape on the sensor causing bad readings