Hey guys, I don't drive this truck much but I just put in a new oil cooler while I was doing an EGR by-pass about 500 miles ago. I also did a full flush installed a coolant filter, new blue EGR hose. I had a pretty good delta (8-9 degrees) up until the last month or so when I noticed the temp delta was pushing the 20 degree mark, today (95 degrees outside) the delta reached 24 degrees, what could be happening here?

Thanks in advance!

 

Dang! Did you do the flush from the Tech Folder? I've seen a few other threads where this happened and the poster(s) usually blame it on trash in the coolant system loosened up during the flush recloggin the new oil cooler. Do you have a coolant filter installed? It would be interesting to cut it open and see how much stuff it caught after the flush. Also, most of us look at gauges that are reading the data buss and dont think much about the actual sensor. If it's not too expensive maybe changing it will get you a lower oil temp. Also are coolant temps UP where they should be? Damn aggervating to do all that work and still not right!

 

I do have the the Dieselsite filter in place and I get good flow and extremely clean coolant though the whole system. I never did the VC9 flush because everything was really clean when I did the EGR by-pass. I only changed out the oil cooler because I was already in there. I thought about swapping out the sensor but my EOT and ECT temps are nearly identical after a long "cold-soak" i.e. not runing for a week and then when I do run it the temps stay well with in an <8 degree spread until the ECT reaches 190ish and the EOT keeps going up until it levels off at around a delta of 24 degrees (it's maddening). ECT has always hovered around 190ish, even on big hills.

 

Hate to even think this way Cody, but you may want to put a pressure gauge on the degas bottle.

I believe the oil temp sending unit is the same part as the coolant sending unit. If you would swap them with each other and the temps stayed the same as before, then you can be sure it isn't a sending unit issue.

Also, the post for backflushing the oil cooler (from the oil cooler cover plate - at the hose to the EGR cooler), MIGHT be worth doing, but it just doesn't sound likely that you could have so quickly plugged a new oil cooler.

 

Oh good idea. I'll give the sensor swap a shot and see if the sensors are sending the same values.

Would you happen to know where I can get the degas pressure gauge? What pressure should I be seeing at operating temps?

I agree, I just can't imagine that with a coolant filter and everything being so clean and fresh that the cooler could be plugged. If all else fails, I've give the back-flow a shot. I really really really don't want to pull and replace everything I just did ~500 miles ago.

Thanks Mark

 

I use a low tire pressure gauge. Its for lower PSI levels when using slicks at the drag strip or dirt track tires. My gauge reads from 0-30. You can get 0-15 too. Bought it at a dirt track speed shop.I bought a gauge with fittings so I could mock it up how ever I needed. Still on the truck,and will be for as long as I own this truck.

My PSI has not gone over 12 no matter how I run the truck since repaired.

I would like to know what the normal PSI reading is as well. Not what Ford says is acceptable I would like to know what the Techs feel is a comfortable PSI reading.

 

I just "tapped into" the upper hose on the degas bottle. I have an extra fuel pressure sending unit that I connected to it so I could watch the pressure from the cab (I wanted to see what it did at WOT).

The most I have seen is 12 psig and that is when it is hot outside and my coolant temps get to 210*F or so.

I think the Ford limit is actually above the 16 psig cap rating for getting concerned over head gasket leakage. A Tech will have to jump in on that for more specifics (it has been awhile since I have read the TSB's on it).

 

Oh guys, it occurred to me and I forgot to mention that the way I did the EGR by-pass on my truck would make it impossible to the EGR cooler to have any effect on the rest of the system. I sealed both ends of the round EGR cooler so even if it did leak it would just turn into part of the water jacket and would have zero effect on the system.

 

I don't think the operating pressure will tell you as much as what testing the cap/system by pumping it up to 16 psi and seeing if the pressure holds will. However,if an operating pressure of say 5 psi is observed,your cooling effencice would be severly deminished but you still have to find what is failing to hold pressure.

 

I went 400 miles before mine plugged on me.ended up putting a new radiator in my truck.all the flushing knocked all the scale in it loose.I was lucky though,I back flushed the cooler and saved it.I'm on 600 miles now and did see a ten * spread with an ambient temp of 90 doing 65.but normal for mine is 8-9. I would definitely backflush it,sounds like it may be plugging on you.

 

Just be sure to do the pressure test w/ cold fluid as it will contract as it cools and the pressure will drop from that (but it should be a very slow rate of decline).

One time when I got to 10 psig in the degas bottle, I shut it down just to see if it held pressure. It held this pressure for hours. Not a bad test I would think.

 

What will the degas pressure tell you about a 20* delta?.did I miss something when mine plugged so quick?.something else I shoulda done?.

 

Just being cautious around head gasket leaks. They can certainly cause coolant temp spikes and puking, but they can also restrict coolant flow and cause the oil temps to increase.

My fault on getting so side-tracked w/ the pressure test.

If your coolant temps are staying very close to 190, even when working it hard, I would think that it is unlikely to be head gaskets. Still hard to believe the new oil cooler could plug so quickly.

 

Ok,gotchya bismic.I was very disappointed to say the least when mine plugged at 400.had a couple cooling tubes in my radiator plugged off by scale,it was terrible.

 

Do you think a shot of VC9 would free anything up or perhaps just plug it up worse?