om617 high egts and water temp - Page 2 - PeachParts Mercedes-Benz Forum

BillGrissom · #16 10-07-2015, 02:31 PM

I kind of lost you on pondering a motor change to fix an overheating problem. Unless your current motor is terribly inefficient, any motor will need to reject about the same amount of heat for the same power output. That is basic thermodynamics. Get an IR temp gun (cheap at HF) and verify the head temperature. Focus on the radiator and coolant flow.

jacobbeuk · #17 10-07-2015, 10:51 PM

I have. a brand new thermostat in it and drilled the hole in it in hopes to get better flow with the other radiator and I haven't tried it with my aluminum on yet and my egts probe is brand new so I hope it's not ruined and as far as swapping motors I would going to a 2.7 tacoma if I can't make the 617 work and I don't know how to test the spray of my nozzles

mannys9130 · #18 10-07-2015, 11:20 PM

Kinda sounds like you did the swap without researching too much about the 617s.

Replace the thermostat with holes drilled in it. It's not necessary. The thermostat does two things at once. It opens flow to the radiator and closes flow to the bypass. Under operating temp, it bypasses. At operating temp it is open at bath places, partly adding to the radiator and partly bypassing. At 90*C (I believe) the thermostat is totally sending coolant to the radiator and the bypass is totally closed.

If your boost is only 8 psi, it's low. Hopefully your ALDA is intact. If it was removed or turned all the way up, that coupled with your low boost is a bad recipe. Running rich in a diesel is the complete opposite of running rich with a gas engine. It makes EGTs skyrocket. 1600 F is absolutely ridiculously high. You'll melt piston crowns, burn exhaust valves, etc. You need to be down around 1000 or 1200.

charmalu · #19 10-08-2015, 12:43 AM

You will have to remove the Injectors and take them to a Fuel Injection shop
and have them tested, and or rebuilt if they have a bad spray pattern.

Pull off the return lines with a pair of pliers.

Remove the hard lines with a 17mm open end wrench.

Use a deep 27mm socket or 1 1/16" 12 pt to remove the Injectors.
Make sure it is a deep one so the 2 return nipples do not get damaged.
Most sockets they make today are only 1/2 as deep as the length of the socket.

The one I use is a craftsman 47532, but the one they make today is not a deep.

When you replace the Injectors, be sure to replace the heat shields,
and new rubber return lines.

Charlie

sent from my pos computer

kestreltom · #20 10-08-2015, 05:31 AM

Quote:

Originally Posted by jacobbeuk

... I am just wondering if that aluminum radiator will make that big of a difference vs the stock one i had in it cause I need to buy another adapter plate for it but I don't wanna keep spending money on it if I can't fix the problem and how about getting my egts down?

I installed an aluminum 3" core radiator from Northern on my 300D and it improved cooling enough that the electric fan does not come on all that much. It is better than the stock radiator.

I think your problem is somewhere else. The egts will come down when you enough boost to the engine. The stock turbo is limited in that department. Are you getting a lot of black smoke?

Skippy · #21 10-08-2015, 06:55 AM

1. I didn't see a number of how high the coolant temp is actually getting. How hot is it? Measured how?

2. For EGT the fueling needs to match the boost. A properly working ALDA will do this for you. Many ALDA's are no longer properly working. Most fail in a low fuel mode, but I could imagine it failing the other way. Boost should be 10 psi stock, but others have turned the wastegate up to 12-13 without an intercooler. How much is it smoking? Should be none to very little at sustained WOR.

3. Holes in the thermostat doesn't help. Put a new one in.

4. You are running a 50/50 mix of water to coolant, right? Straight coolant doesn't cool as well. Straight water can carry more heat initially, but will eventually lead to corrosion and scaling.

5. Sometimes the impellers on the water pump errode causing the pump to not pump as well as they should but without causing leaking through the weep hole. After 1-4 are addressed, if it still overheats you might consider changing water pumps.

If the radiator you're running is the one from a 3VZ-E V6, it should be able to cool a properly running 617 as long as it's in good condition and everything else is working properly.

Simpler=Better · #22 10-08-2015, 10:21 AM

Don't scrap the engine, you can get it sorted out pretty easily. Injector rework is around $100-$200 (total)depending on parts/condition etc.

BillGrissom · #23 10-08-2015, 03:30 PM

kestreltom,
The electric fan is actuated by the AC condenser outlet temperature, and the condenser is in front of the radiator, so not sure why the radiator temperature would affect it significantly.

If the over-heating is due to an inefficient engine, I would think that would be noticed by poor hwy mpg. Of course no data for a "normal" OM617 in a Toyota, but at least compare to the factory mpg. Unless the engine is idling real rough or pouring out black smoke, it is hard to imagine it is running poorly. If you are over-fueling it, that would generate excessive exhaust heat, but you would also have black smoke. If the radiator is the problem, another engine won't solve that.

jacobbeuk · #24 10-09-2015, 02:57 AM

Skippy the radiator was a brand new one from the 3.0 v6 Toyota and as far as it running hot it only does it when I pull big hills or really hilly roads and it goes over 210 degree even with my electric fan running non stop and I will adjust the boost level and install a new water pump and my aluminum radiator and it doesn't smoke unless I really get on it and it isn't that much when it does an ways and I also install a new thermostat and how do I test if my alda is good or bad? And my electric fan is a aftermarket one. And sorry for the delayed responses I work on boats and we just came back to port

jacobbeuk · #25 10-09-2015, 03:13 AM

And sorry about the engine swapping I was meaning if I can't get the EGTS and water temps down then I will have to do a different motor but I really wanna make this work but I don't wanna dump a bunch of money into it if it is not gonna work

Skippy · #26 10-09-2015, 08:16 AM

210 isn't really that hot. The manual says real overheating is over 120 C, which is 248 F. Mine has been running 100 C (verified by IR gun as 208 F at the head) for years whenever warmed up. I'm still a bit concerned about 1600 EGT, which is way hot if accurate. Not smoking (much) is a good sign. Is the ALDA hooked up to the intake manifold?

Maxbumpo · #27 10-09-2015, 08:44 AM

Quote:

Originally Posted by Skippy

210 isn't really that hot. The manual says real overheating is over 120 C, which is 248 F.

Bingo, diesels like to run HOT! 210 deg F is just below 100 deg C, and normal operating range for your engine is between about 82 deg C and 90-95 deg C. You may have a calibration issue with your dash engine temperature gauge, need to check that with the aforementioned non-contact thermometer.

Also, before this tidbit, it occurred to me that if you HAD overheated the engine (coolant-temperature-wise) then your MUST replace the thermostat, as the wax pellet inside that controls the movement can be damaged and is no longer reliable.

High EGT is another matter, if your engine hasn't seized and doesn't make bad noises and/or use too much oil, then you most likely don't have damage yet.