..

 

HI!... Unless your running under drive pulleys with that COBRA "R" pump, you are creating a problem with coolant flow. See the "R" pump flows more fluid than your stock W/P does. By running the "R" pump with under drive pulleys you are spinning it at about the same RPM as the stock pump with stock pulleys, but because the "R" pump is more effecient at pumping the water you will actually gain a bit of H.P. Running the "R" pump with stock pulleys is actually costing you power. It would also mess with your cooling system. You should also upgrade to two 16" DERALE electric fans. The 210 is junk IMO.

 

...

 

ROUSHFAN-1, did you try replacing the thermostat yet?

Did you notice any antifreeze in your oil or vice-versa?

Good luck.

 

.

 

Hello Roushfan,

I appreciate your confidence in my ability to solve your problem, that's very kind of you.

However, we do not diagnose vehicle problems on the Internet, that isn't what we do nor is it really possible to make a correct snap diagnosis on a vehicle we can't see or test.

Just as a quick reminder to everyone, we do not operate a vehicle repair shop, we are a *performance* company, so what we do is improve the *performance* of our customer's vehicles by supplying performance parts and installing performance parts. I wouldn't begin to call us true repair diagnosticians, as I have far too much respect for those who actually *are* to claim that.

I'll make this 1 exception to try to help you, just this once, along with a reminder to you & everyone else to please not ask us to diagnose problems with your vehicles here. That's when you need to consult things like service manuals, the search feature here if someone in an appropriate section of the message boards (which isn't here in the Computer Chips section) can't help you, and your local mechanics are for.

So with that agreed to............

Using the Cobra R water pump doesn't get you much on engines other than the factory-supercharged 5.4's found in the Lightnings & newer Harley models, which will see 3 to 4 more HP from that pump. If you have a set of underdrive pulleys from us here at Performance, then that's OK, as our underdrive pulley set for the late-model F-150 & Expedition with either V8 engine has a separate pulley for the water pump that speeds the water pump back up for proper coolant flow thru the engine. That being the case, **on the surface** I would not automatically assume that you have a basic lack of coolant flow thru the motor that is due to the water pump being turned too slow. Normally that is something I *would* look at with symptoms as you've reported, and if other measures don't work, this should be re-visited.

However, where I would start in this case is to pull the thermostat and check it. Compress it's spring manually (with your thumbs) and see if it feels smooth & linear thru it's entire range of motion. Does it feel a bit "sticky" in places, or perhaps have a bit of a "notchy" feel to it anywhere thru it's entire range of travel? If it is *anything* other than perfectly smooth & linear, I would replace it. Thermostats don't just fail open, contrary to popular myth, t-stats can fail open, can fail closed, can fail and still move, etc. For example, when you overheat, one of the easy things to try to get back home is to tap on the t-stat housing, to free a stick spring mechanism. At any rate, check that t-stat and don't hesitate to replace it, Hypertech's t-stats aren't any better than anyone else's, and you cannot depend on them (or any other t-stat) to conveniently stick open when they fail. One one of our 2001 F-150's here, the factory t-stat worked fine most of the time, but once in a while would catch, or stick mostly closed, etc. & slow down or just about stop coolant flow to the radiator, and it didn't have many miles or age on it. Any t-stat can fail at any time, new or old. We usually replace t-stats in our vehicles every year (the ones we keep long enough, that is).

I really don't think your electric fan has anything to do with your stated symptoms (unless this happens at lower speeds), as once you have about 35-40 mph of road speed, you generally don't even need a fan to cool the motor as you've got enough airflow just from roadspeed alone thru the fins of the radiator to keep the engine coolant temp in a normal range. So as long as the fan is mounted in a "puller" orientation behind the radiator (on the engine side of the radiator), it shouldn't be blocking airflow thru the radiator at higher speeds.

I would really pick up a service manual for that vehicle, and while you're diagnosing this problem make sure and "burp" all of the air out of your cooling system. They do have a "de-gas" bottle instead of a conventional radiator cap these days, but that doesn't get all the air out of your system just by itself right away, so I'd "burp" the cooling system, as that is a potential cause for your symptoms as well.

Good luck my friend!

 

Thanks Mike for the response..Hope i didn't open a can of worms! I know your wayyy tooo busy as is !!

 

Hi RF-1,

You're more than welcome, I try to help when I can. Actually, I'd like to be able to do nothing else all day but read & respond to people here, tryign to help, if only I had the time!

Good luck with your problem, & do let us know what you find, ok?

Have fun,

 

Thanks Mike,Neal,Le pew ..It was the T-STAT......

 

Hi Roushfan-1,

Ok, simple solution thn, glad to hear it was just the thermostat.

Have fun & maybe now you can really enjoy your weekend since your truck won't be overheating any more!!