Just swapped the oil cooler and welded the egr cooler shut after flushing the system with restore and restore plus. Additionally I have been running ELC with a coolant filter for over 40k miles. After all that I'm seeing a 12 degree delta. I was hoping for less.

This got me thinking though. I run an SCT with mild custom tuning, atlas 40 FICM amongst the other mods in my sig.

I also have an 8" lift and 38" tires. The tires definitely make the engine work harder compared to stock tires.

In my scenario does the 15 degree delta even apply?

 

I would only discount those numbers if I had a remote oil cooler installed. 12 is kind of high after a cooler change.

 

Hope you did the flush BEFORE the oil cooler change..... I believe that's what you said.

What are your numbers after an overnight cold soak WITHOUT your engine running?

 

The guages work fine. Cold soak numbers are just a tad higher than ambient air temps.

Again the truck was flushed 40k miles ago, elc added and a coolant filter installed.

Flushed again 2 weeks ago with restore and massive amounts of water.

Then the truck was then driven for a couple hundred miles prior to cooler swap. Everything was done the right way.

I will add that the cooler appears to function properly in that the second I pull off the freeway the temps instantly start dropping.

I guess I should also add that I have a tool box with a few hundred pounds of gear.

I'm considering the Absolute Performance Delta kit for peace of mind...

 

1) After an EGR delete, the 15 degree "rule" is no longer valid. However, keeping an eye on the spread is an indication of oil cooler health.

2) I would expect far better spread than 12 degrees @ 65 with a new cooler. Although, by your results you mention it cools off rapidly after slowing down which is a good thing.

3) With that said I would suspect a possible weak oil cooler bypass is contributing to the higher temps at speed.


Josh

 

I would have thought the rule applies for a couple reasons.

Oil cooler.... 15* spread because of plugged passages.
EGR is coolant and exhaust gasses, really nothing to do with oil temps. Removing the exhaust flow would remove some heat, but since it doesn't directly touch oil, I'd of thought that deleting it wouldn't really affect a plugged passage in the oil cooler.

Flawed thinking?

 

When you delete the EGR cooler you remove some of the load on the cooling system which is where this discussion stems from.

 

With no functioning EGR cooler, what difference does the spread mean? The only limit is then the 253 de-fuel.

I would still change the cooler once it hit a spread of 15-20. I wouldn't consider it mandatory the cooler is changed with no EGR cooler though.

Josh

 

Agree'd... But I would think not more than a couple degrees... plugged is plugged, if the coolant can't reach the passages, won't matter much.

 

The oil cooler may get slightly plugged but it won't matter as much as if the EGR cooler was present. You don't have to worry about boiling the coolant in the egr and rupturing it.

 

I would think that the oil cooler with cooling provided by the water was more signification than that. Cooling happens in the heads as well and some other places. What would the significance of the oil cooler then be? Was the cooler added because of the EGR?

Edit... maybe I'm thinking to much like a gasser... it the only oil cooling happening at cooler.

 

huh? More significant than what?

 

if oil cooling happens throughout the motor, then what purpose was the oil cooler... to provide more cooling, so oil temps wouldn't get out of control (defuel). So it does serve some purpose and should provide a level of efficiency.. if it provided nothing, then why not just bypass it all together? And basically is what your saying, that once the ERG cooler is gone, it doesn't muck matter... that what I'm hearing?

I'm all about learning something...

 

Oil cooling doesn't happen throughout the motor. Nothing in there cools down the oil. The oil cools down internal parts though.

If you had no oil cooler, the oil temps would get HOT in a hurry.

 

<br /><br /><br />
The spread is there to protect the EGR cooler from being starved of coolant from a plugged oil cooler, once the EGR cooler has been removed the importance of the temp spread has been diminished significantly as there is no danger of rupturing the EGR cooler due to lack of coolant, however the spread will still indicate a plugging oil cooler and reduce its ability too properly cool the oil so at this point the main concern is how high the oil temp gets, so now the deciding factor on when to change the oil cooler is not solely based on temp spread but what the max oil temperature becomes.