runs to warmfor me

[Plandon]

93 dodge ext cab auto stock, changed fan clutch,thermostat,rad cap, rodded out rad still runs in the middle and higher. Have super cooler on trans 109,000 miles all other trucks meaning 3 93 dodges all cummins run at 2nd peg on guage what am I missing. I'm in arizona near Phoenix. I know i"ve asked the same question before but haddn't rodded rad before Thanks Guys

 

[Paychk]

Make sure you are using the latest CUMMINS thermostat, a lot of other brands have had problems reported.



The manual states that the thermostat only guarantees minimum engine operating temperature , after 181 degrees is reached, the engine temp is controlled by the radiator, fan and ambient temp. Have you check for dirt stuck in between the a/c condenser, inter-cooler, and the radiator? Also check and see if it is possible the fan is mounted on back-wards?

 

[cerberusiam]

The best way to see if you have a heating problem is to put a mechanical gauge on it and see what the temps are. It could be a bad sending unit or gauge that causes the readings. You didn't detail when the temps got to high for your liking. All the time? Running at hiway speeds? In traffic? Mine will bounce between the middle and second mark most of the time. Under a load it sits dead in the middle all the time. At any temp over 100 degrees and 75 mph it is pushing the third mark constantly. The outside temp makes a big diff in where the temp gauge is reading. Summer in Phoenix when I lived there you were lucky the temps got under a 100 degrees for a low. That would definitely cause my truck to read higher than normal. The only way to know for sure is use a mechanical gauge and check the actual temps.

 

[Plandon]

to warm for me

If I am running down the road at 60 mph empty it will run up past the third mark if I am haul my water wagon from town up to my house there is a slite incline for seven miles(1000galwater). We have 3 other dodge trucks same year same engine all stock 2 d250s one auto one 5spd 1 d350 5spd 298,000 miles all of them you can't move them off the third peg from the cold mark I'm missing some thing maybe guage I'm picking one up tonight wish me luck. thanks

 

[JLEONARD]

You should verify that what the gage is reading is correct by using an infrared thermometer. Then you will also know what those little lines on our unmarked gages really mean.

"Shoot" the gun at the sending unit if possible for the best results.

Usually it's the sender, not the gage.

Also make sure you have no air pockets in the system.

Mine stays on the first major line... it never varies more than the needle width, no matter what the air temp is, no matter what's in the bed, no matter where my foot is and for how long it's there. That equates to about 170 ish as I recall according to the readings I've taken with my temp gun.



Good luck

Jay

 

[Plandon]

to warm for me

Last night I installed a temp guage it is exactly on the money with truck guage. Just cruising down the road 55 or 60 it will climb to 190 then if you work it very hard she starts to climb from there so far not to boiling . Anyone have anymore ideas I'm stumped.

 

[dpuckett]

PLandon,

Have you done a cooling system flush? CLeaning out the radiator is only half the equation. The head and/ or block could have obstructions in them as well. When I did my head gasket recently, the gasket had enough build up in it that only a little water (think pin hole size) was passing through it. If your rad was in bad shape, it's a good bet the head and or block arent operating at their peak efficiency either. Might end up (gasp) pulling the head and cleaning it all out. Might also try a cooler t-stat. I know you can get 175s for our trucks. Mine normally runs on the 2nd connected mark, goes up to the middle for a bit if I am pulling a load uphill in 100deg weather. Hope this helps.



Daniel

 

[jtwcummins]

Don't know if this applies to 1st gens, but the thermostat on my engine is 2 stages. Coolant starts thru the system at about 140 degrees. In stop and go or pulling at between 180 and 190 the themostat opens completely and the temp drops quickly to about 140 again. The clutch fan is also fully engaged.



The factory 'stat never let temp go above 140 so I replaced with a Cummins upgraded unit, seems like alot of owners complained that their trucks never warmed up so DC and Cummins replaced, at $35, with one that let engine get to a good running temp.

 

[Plandon]

(to hot for me) still know change

Ok boys,now think harder. I've done everything , just put in new water pump & belt today. Now we have new pump ,belt stat, rad cap, bottom hose, fan cluth,fan rad rodded out,mech gauge. She still gets up to 190 pulling a load home (1000gal water ) on trailer pu slite incling. I know if the distance was longer she would get hotter , all our trucks will do same load no problem there the same vintage 93 dodge HELP!!!!!

 

[jtwcummins]

An engine can run hotter than normal if:

The timing is off

fuel supply is to lean to cylinders

Not enough cool air is getting thru air filter to engine, only hot air from engine compartment

 

[cerberusiam]

Looks like you have done all the obvious things and if the air flow is good thru the radiator it may be time to dig deeper.



Maybe pushed a head gasket internally? Most of the head gasket problems I have seen have been external but who knows. Worst case it could be a cracked head or exhaust valve seat. The early motors had a problem cracking heads until they went to a smaller injector but some later gen 1's have been known to warp and crack also. Post the fix when you find it and good luck.

 

[Plandon]

jtwcummins, About timing just, looking at it the pump marks line up dead across from each other ,now do you mean to maybe advance it alittle or is mar to mark good? As far as being to lean on fuel, are you talking adjust that screw with the cap and welded jam nut on it. I had it emission tested the other day . The standard was 40 mine tested 5. 4 opacity. So I figure I mite have some leway to turn it up. But I thought that would increase heat?I guess I need more instruction. I also think I mite take cerberusiams advice and get a compression gas anylizer test. Just to check for hot gas leak to cylinder,boy I sure hope thats a big negitive.

 

[jtwcummins]

timing, if advanced to far will cause heating. Lean means not enough fuel getting to cylinders for the amount of air, like a bad injector or anything cutting the amount of fuel down or increasing the air like leaking intake gasket. Any vac leak leans out the engine. There are a multitude of mechanical things like headgasket. Are u loosing cooling fluid or oil. Any water in oil, or fuel?



If not loosing fluids I would verify timing and fuel pump volume. Make sure valves are still timed properly since a timing chain can jump a tooth.

 

[cerberusiam]

One thing to keep in mind is a diesel does not pull vacuum and the engine is direct injected so given the aneroid is working correctly you will not see a lean condition from an intake gasket leak. Intake and/or intercooler leaks usually show up as low boost, loss of power, and in some cases excessive smoke. The injectors can plug but usually deliver enough fuel to make the engine run correctly up to certain rpm. Bad injectors can cause rough idle, excessive smoke, and most noticeably a loss of mileage. If the truck still runs good, pulls good, and you don't have a lot of white or black smoke its probably not in the air/fuel system. If your timing was advanced far enough to cause heating problems you would have a very noisy motor. Something on the order of a washing machine full of marbles would be close. Just pushing much past 16 or 17 degrees causes a rapid increase of noise at an idle and really bad under load.



I have had 2 engines crack the exhaust valve seat and the only indication there was a problem was excessive coolant heat. It didn't boil it out or overflow the catch can or leak into the oil they just ran hot when loaded. Granted, the problem engines were gassers but the pricipal is the same. A small crack can bleed combustion heat into the coolant systen and not leak the other way. I assume you have checked and replaced the air filter. It was very noticeable on the non-intercooled models when the air inlet was restricted. They heated more than usual. Have not had that problem with the intercooled truck but I change the air filter regularly.



The only other thing I can think of is a partially blocked cooling passage to around the temp sensor. Its at the back of the block and could possibly be warmer than anything else. Where did you tap for the manual sensor? Is it toward the back or front?

 

[cerberusiam]

Plandon,



Here is another thought. Have you done anything with the exhaust system? Does the truck still have the OEM muffler and tail pipe? It could be a simple thing as exhaust restriction causing it to heat.



Rereading the post you said you are hauling a 1000 gal water tank, the truck is an auto, and 3. 54 gears. Your truck should be around 6000 lbs and at 8 lbs/gal (I think) for the water your GCVW is around 14000 lbs. More if you have a trailer under the tank. In high ambient temps and a 7 mile incline my truck would be pushing the upper mark also. 'Course I am pushing more fuel and making more boost than stock so that could account for the temp rise.



Just curious about the differences between this truck and your other ones.

 

[jtwcummins]

sorry about using the word vacuum, meant MAP, manifold absolute pressure. A diesel w/o a turbo has pulses of vac but turbo maintains positive pressure in system. Replaced an intake gasket for one owner. It was pulling alot of air in by cyl 5-6. Hot air off the engine. The truck seemed to run okay but ran hotter than normal when pulling.



What are the chances you have a loose valve, adjusted lately? One loose valve can cause engine to run hot under load and not make much audable noise.



Timing, when both #1 valves are closed are the timing marks where they should be?



Problem is, the Cummins is such a solid engine it's hard to trouble shoot w/o knowing EGT and boost and being able to put hands on. It takes major problems to effect idle/normal driving, problems do show up when under a heavy load.



Basically I am trying to avoid saying pull the head to clean water passages.

 

[Plandon]

runs to warm for me

cerberusiam; I installed the after market sending unite in front by the thermostat, they read the same. I removed the muffler last week did nothing didn'tr even help with power. I can pull the samw water trailer qwith all three other trucks and they run cool. 1 is a d350 5spd dulley 300,000 miles,1 is a d250 auot no hd trans cooler 80,000 miles,1 is d250 5spd 170,000 miles, all stock. I have not adjusted the valves yet. I'll try it if you think it will help. Fuel and air not really a problem though, ya think?The truck seems to run pretty good,I'm like everybody else I want more power but am afraid to turn it up until I figure out this problem first.

 

[cerberusiam]

If the power is good and no excessive smoke I would guess its not a fuel\air problem. If you haven't set the valves it wouldn't hurt. My valves were looser than they should be but I will defer to jtwcummins as he has seen it cause heating problems. Its entirely possible a manifold leak could cause the problem also. I have had boost\intercooler leaks but no manifold leaks so am not sure. Rather than tearing into engine I would put a boost and EGT gauge in it and see whats happening. Thats about the best way to determine if there is problems with air\fuel or leaks. Gauges are a good investment and I would go that route before pulling the head. Post the gauge readings here and I am sure several people will jump in if they see something that looks strange. Good luck.