Hard start when cold
Fleet Mechanic
Joined: Jul 2018
Posts: 1,629
Likes: 103
From: Jacksonville Florida
There's an oil cooler replacement in your future. OEM coolers are best . don't bye the cheepos on Amazon or you will be doing again in near future.
Flush your motor really well before you replace your cooler. There are good Diesel Tech Ron videos on both flush and cooler replacement.
Flush your motor really well before you replace your cooler. There are good Diesel Tech Ron videos on both flush and cooler replacement.
Fleet Mechanic
Joined: Nov 2016
Posts: 1,343
Likes: 94
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Brett Foote
Fleet Owner
Joined: Nov 2003
Posts: 27,918
Likes: 3,637
The assembled Oil Cooler Housing and internals is obsolete.
The upgraded core is available everywhere. That is what you want. The part # is 3C3Z-6A642-CA.
Your temperature differential is quite high. Assuming oil and coolant temperatures are essentially the same on a totally cold engine, then installing the updated oil cooler core is a high priority.
Also, the SCT is not a good code reader at all.
The upgraded core is available everywhere. That is what you want. The part # is 3C3Z-6A642-CA.
Your temperature differential is quite high. Assuming oil and coolant temperatures are essentially the same on a totally cold engine, then installing the updated oil cooler core is a high priority.
Also, the SCT is not a good code reader at all.
Cargo Master
Joined: Nov 2015
Posts: 3,427
Likes: 940
From: Fort Worth, TX
With an engine bay that looks like that, I can't imagine the truck is having problems. Or am I just being a snob? Really though, that poor truck looks like it's been rode hard and put up wet.
Anyway, what year is the truck? I'm not sure about the newer years, but the 03's and early 04's stock banjo bolts have built-in check valves to maintain fuel pressure in the rails. I bought the 6.4 banjo bolts and never installed them after reading about it. I've been considering replacing the stockers just for the purpose of preventative maintenance.
You say your HPOP is 647 at idle. I just tested mine and its 860 at idle after a cold start and drops down to 750ish after running for a few minutes. Maybe the difference is due to my Dieselsite HPOP. I'm sure Mark will chime in on that one way or another.
If your problem was to do with high oil temps it would be a hot start problem and not a cold start problem, but you will have hot start/run problems very soon if you don't replace that oil cooler.
Anyway, what year is the truck? I'm not sure about the newer years, but the 03's and early 04's stock banjo bolts have built-in check valves to maintain fuel pressure in the rails. I bought the 6.4 banjo bolts and never installed them after reading about it. I've been considering replacing the stockers just for the purpose of preventative maintenance.
You say your HPOP is 647 at idle. I just tested mine and its 860 at idle after a cold start and drops down to 750ish after running for a few minutes. Maybe the difference is due to my Dieselsite HPOP. I'm sure Mark will chime in on that one way or another.
If your problem was to do with high oil temps it would be a hot start problem and not a cold start problem, but you will have hot start/run problems very soon if you don't replace that oil cooler.
Cargo Master
Joined: Nov 2015
Posts: 3,427
Likes: 940
From: Fort Worth, TX
Generally speaking, I agree, but it isn't always gospel. I had two new Motorcraft oil pressure sensors (low pressure) go bad in a matter of months. Replaced with Autozone part with a lifetime warranty and haven't had a problem in three years.
Cargo Master
Joined: Nov 2015
Posts: 3,427
Likes: 940
From: Fort Worth, TX
The suggestion that your engine bay is that way because the truck works hard is ludicrous. There are plenty of hard-working trucks around here that don't look like WW3 took place under their hoods.