Strange question, but how hot is the valve cover on your om617 after normal operation?

I am just finishing up a swap of an om617 into a toyota 4runner. Using the mercedes cooling system. I have the toyota temp sensor hooked up to the engine side of the thermostat housing, and oil pressure sender adapted to the stock location at the base of the oil filter assembly.

I have what seems like normal engine coolant temps. The toyota gauge slowly rises and sits about 1/3 from the bottom of the range. Temperature will rise in traffic at idle, but the 12" merc auxiliary fan is enough to bring it right back down. There is good oil pressure, that goes down slightly at idle when warm, and up with engine rpm.

What has me troubled, is that after going for a drive the valve cover gets so hot I can't hold my hand on it.

I just hooked up my egt probe today, and was not able to get over 950f preturbo.

The oil cooler has been mounted in front of the radiator, and the supply side does seem to get warm/hot, but the return is much cooler.

I reset the valve lash yesterday, only 3 or 4 needed slight adjustment.

I will try to get IR readings of the valve cover and engine, but I have to assume by feel that the cover is over 200f. Also to see if I can get a reading off of the cam shaft through the oil fill.

Any thoughts and feedback are appreciated.

Begin by confirming the accuracy of the temp gauge that is in the cab. What temp & brand thermostat did you install? Is a fan shroud installed to direct air flow properly?

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85SD 240K & stopped counting painted, putting bac together. 84SD 180,000. sold to a neighbor and member here but I forget his handle. The 84 is much improved from when I had it. 85TD beginning to repair to DD status. Lots of stuff to do.

Thanks for the response.

I put in a wahler, 617-200-18-15-M2, 80*C. I am running the fan as a pusher, virtually no gap to the front of the radiator.

Picked up an IR gun today. Preliminary checks seem good. Front of the valve cover is 205f, middle 160f, rear 175f. Oil cooler hot side is 175f and exit is 149f.

Intake manifold was >205, but I can't remember what.

I guess my sense of touch wasn't as well calibrated as I thought.

I need to order thermostats. Wahler is the OE manufacturer.
Does temp hold solid? Some aftermarkets let the temp wander a bit.

Peach says 3 weeks to receive Wahler but they seem to be readily available elsewhere.

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85SD 240K & stopped counting painted, putting bac together. 84SD 180,000. sold to a neighbor and member here but I forget his handle. The 84 is much improved from when I had it. 85TD beginning to repair to DD status. Lots of stuff to do.

Those temps sound right to me. Yes your valve cover should be too warm to touch after a drive.

What were your driving conditions that you couldn't top 950F EGT? I can get to 1100+ but takes hill climbing at high RPM and WOT for some time to get there. 4th gear 60mph foot flat on the floor.

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617 swapped Toyota Pickup, 22-24 MPG, 50k miles on swap

I think it should be hot enough to burn you honestly.

A few days ago I tightened the hardline injector nut and accidentally touched the valve cover with my wrist, instantly scaled by it. It made me recoil back, but I had no injuries or marks, unless and slip and fall, and brace your hand upon the valve cover.

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1998 Ford Escort ZX2 5 speed - 279,000 miles My Daily

1992 Mercedes 300D 2.5 202,000 - Pure junk
2000 Mercedes E320 Black - 136,000 miles - Needs repair

Don't forget to grease the screw and threads on the spring compressor.

If the engine is driven long enough to thoroughly heat up, I'd expect the valve cover to be somewhere close to the temperature of the oil circulating in the engine since that's what's splashing up against it all the time. Valve cover should be hot enough that you risk burning yourself by touching it. Temps >120˚F can cause blisters, Temps >140˚F can cause scalding

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Current stable:
1995 E320 149K (Nancy)
1983 500SL 120K (SLoL)

Black Sheep:
1985 524TD 167K (TotalDumpster™)

Gone but not forgotten:
1986 300SDL (RIP)
1991 350SD
1991 560SEL
1990 560SEL
1986 500SEL Euro (Rusted to nothing at 47K!)

Thanks for all the excellent responses! I feel a lot better now.

OM617YOTA, I5 south from Vancouver to Portland, 950* egt in the morning. I hit nearly 1100 on the way back north in the afternoon.