Diesel Temperature thread

[DaveB]

I'm trying to figure out if my Peugeot 2.5 TD in the series truck is running too hot, too cold, at optimum temp, or if I'm just worrying too much.

So, any of you with diesels, if you have an aftermarket temperature gauge with actual degrees showing, would you chime in please?

Here's what I know so far:

Thermostat works, and is full open at 180°F (brand new), and the proper unit for this engine with bypass shutoff.

50/50 mixture of water and antifreeze, thus boiling point of 265°F

10 lb rad cap, new, which should increase boiling point by 30°F

Brand new 4 core radiator, from Rovers North, their Proline model.

Autometer Temperature gauge with sender at back of engine.

16" electric fan with adjustable thermostatic control wired into the top radiator hose.

Operating temperatures:

Around town, warmed up, but no significant load: 180-190°F

Highway, warmed up, some load, around 5 pounds boost: 185-200°F

Highway, up steep hills, and long climbs, often on 10-12 lbs boost, at least for short distances: up to 215°F, and rarely to 220°F.

Unfortunately, the Autometer Pyro gauge is in for its 4th replacement as this unit has been faulty from the day I installed it, so I can't tell you what the EGT temps are during the maximum water temperature, but I would imagine I'm getting close to 1100°F for a few seconds.

Am I running within normal temperature ranges with this?

I'm a lot more comfortable with the operating temp now with the new rad than I was with the old, but assurances from others with turbo diesels would be great.

I haven't yet installed the intercooler, which may make a further difference as well.

thanks, Dave

[red90]

Ummm, well, no engine should run hot ever. It should stay near the thermostat point. If it doesn't the cooling capacity is too low.

A diesel is no different than a gasoline engine in this respect. They just need less cooling.

BTW, what are these F things you keep talking about?? :wink: Those died thirty years ago.

[HeadDamage]

My GM 6.2 diesel has temp in C. Runs around 40 to 60 in town stop and go. 80 to 90 on the hwy and if I really hammer it up the steep mountain passes with a load it can hit 110C but I usually back off the fueling and drop a gear if it gets near 100C.

[dan]

My 6.2l diesel does pretty much the same. Max 100-110 when going up the trail hill to rossland on a hot (35 C) day. 280000km and still gives 24-26MPG . Auto with o/d.

[DaveB]

Thanks Guys, those F things kind of match those mile things on my odometer, don't you think?

So to convert, 180F = 82C, 195F = 90C, 212F = 100C, 230F = 110C

I do run normally at 82C to 90C, however, its under heavy load up hills that the temp starts climbing...

Sounds like I'm much in the same range as the GM trucks.

Dave

[dan]

Does turning on the heat inside the vehicle help cool the engine?

[obalme]

It might be a good idea to find out what the cooling capacity and the average run temp's were of the car you took the engine out of.
We have one tractor that will run just below the red line at maximum load no matter how hot it is, the other tractors never seem to run that high in the same conditions.

A good rule of thumb is, if you can smell oil in the cab of your truck it is probably running to hot.
Good luck, oliver

[Glenn D.]

I also had concerns after my new turbodiesel went in. I had a re-cored radiator (more cores than stock) and an electric fan.

I have been losing a tiny bit of coolant and running just a touch hot offroad or uphill (3/4 up temp gauge).
I figured out that the rad cap I had was 9 lbs, and the 200tdi was supposed to be 15-16lbs. I have an new one in the mail.

Day to day with the electric fan (or without!) It seems to run around the same temperatures as yours Dave, 88-89c (using infrared scanner) right after normal easy running, and my temp gauge matches Bill's similar conversion. I hope the little overheating that concerns me will go away with the new rad cap.

I guess the question you (and I) want answered is how hot should it be and how hot is it? Anyone?

[DaveB]

Thanks Guys for the input.

Glenn, unless the small amount of leakage is coming out of the cap, or perhaps bleeding through it — in other words, if the cap is faulty, you're not likely to improve your cooling with the upgrade of the cap. It will, however, increase the boiling point by 3 degrees F (yes, F, around 1.67 C) for every pound of pressure. So with a 15 pound cap, and 50/50 antifreeze water mix your boiling point will be around 310°F/155°C.

Dave

[N Hamelin]

Dave,

My perkins 4.182 turbo diesel is reading exactly the same temp. range as yours. I have also verified these numbers using a infrared thermometer after troubleshooting an overheat condition from the time of install, that ended up being a faulty temp sender! I believe we may be slightly restricted in our efforts to keep things cooler by the limitation in the size of our cooling systems. I have run both mechanical and electric fans on my custom 4 core rad at the same time and believe the problem is not related to the amount of airflow across the rad, but the amount of coolant in the system.

It will be interesting to see if you notice a temp. drop with the intercooler!

Neil