Could someone explain to me what is exactly happening when your EOT vs ECT numbers begin to spread?

From what I understand the oil cooler is clogging which is causing the high EOT number. So, if it's the oil cooler that is failing why does everybody immediately jump into deleting the egr cooler along with the oil cooler replacement?

Also, why does my ECT number have such a big range on normal 60-70 MPH highway driving with no load? Sometimes it runs as low as 186 and others it gets as high as 200. I would expect it to get that high while towing but not on normal driving conditions.

Thanks,

Mike

 

I think for the most part its a " since I'm here" thing on the egr cooler,but usually it fails first due to a clogged oil cooler restricting the coolant flow to it.you don't have to delete it by any means,as long as its not leaking into the intake or #7 cylinder.when im " in there" mines going bye bye ,but thats my preference.you may need a new t stat for your truck.

 

Coolant flow goes from the oil cooler to the EGR cooler. With a lack of coolant flow to the EGR cooler the tubes/fins in the EGR cooler come unsealed from extreme exhaust heat allowing coolant access to the cylinders. Deleting the EGR cooler with oil cooler replacement is a future preventative measure against EGR cooler failure and is typically done at the same time because they are removed at the same time for oil cooler replacement. With the advent of the bulletproof EGR cooler, deletion is becoming less and less common.

FWIW--I don't think your coolant temp. ranges are extreme and 200 certainly isn't high for a diesel even under no load. Your temps may be due to ambient temps, thermostat operation, slightly low coolant level, sensor reading, gauge reading, etc. I admit the range is a little strange but I don't think it's a concern. Are you losing coolant, puking, etc? What's your ECT/EOT spread?

 

I'm not losing coolant. I've been keeping an eye on the that. My ECT is hardly ever at 190* been when it is my EOT is usually 203*. With my ECT numbers all over the board like they are I'm a little hesitant to believe the 13* spread. It could actually be better or worse.

Do you think it's time for a new t-stat?

 

That' would be the first thing to change. You can't really get a true spread with incorrect coolant temps. If your temps stay consistently lower than 190 after a thermostat change then it's possible the gauge or sensor isn't reading correctly.

 

Deleting the egr cooler and replacing oil cooler certainly does not put the issue to rest. As has been advocated ever since the problem was fully understood,coolant flushing,coolant type,coolant filtering,coolant system component maintenance and by all means oil and coolant tempature monitoring with aftermarket guages remains nessary if you want longivitivity and dependability. Point being the new oil cooler will likly become restricted with or without egr components in place if you don't take measures of prevention.

 

da-bees hit the nail on the head.

 

Yes he did and I gave him reps for it. Great post.