Hi,

My 5.8L XL Windsor van is overheating when idling or in traffic but cooling just fine when moving on highways.

The 5 blade-fan comes on as soon as I turn the engine on and the radiator appears to be working just fine, cooling fluid moving and no leaks.

I am a landscaper in NYC and often haul heavy loads through slow moving traffic in the city and would love to drive relaxed and not with my eyes fixed on the temperature gauge awaiting impending disaster.

What is the best course of action?

a) change the clutch and see how it goes...

b) change the clutch, the fan and the water pump

c) install an electric fan

d) drive the van into the east river

Another issue, which has me and my friends puzzled, is that I changed the termostat a while back in an attempt to locate the problem; I replaced the old 195 degrees with a 180. Since the change 8 times out of 10 when I start the van as it is warming up I have to rave the engine for the termostat to open otherwise it does not and I end up with overheating bang. Once it is open no problem beside the overheating while idling.

And one final issue after driving for a while the motor surges when idling at a stop light or in heavy traffic. I have been thinking a bad air sensor but my mechanic or I have not been able to fix this issue for years.

Thank you for your help and feed back.
Ed

 

Check to see that there is resistance on the fan clutch when you try to spin it by hand with the engine off....light or little resistance, the clutch fan is dead...replace it.

A partially obstructed radiator or partially stuck thermostat will cause similar problems.

 

Thanks Beechkid, I tested the clutch today and there is definitely some resistance when I spin the fan by pushing down a blade with 2 fingers from under the van I get an 1/8 or a 45º rotation, which is not much; not sure if that is enough resistance though?

The first thing I did months ago to try to solve the problem was to flush the radiator and change the termostat. I only have the problem when the weather starts to warm up, anytime it is over 80º the van does not like it when sitting in traffic for a while, it gets worse as the weather gets hotter. What I am trying to determine is if this condition is due to a part failure or if it is inherent to an old van, in which case I may be able to upgrade or modify the cooling system for a better outcome.

 

Ok, sounds like the clutch fan is ok..........
I would check the thermostat (change it out again) because they can 9although not suppose to) partially fail....meaning it is not opening all the way, causing just enough restriction to heat up...where on the freeway, you have extra air moving to compensate so to speak.
If still occurring, then i would look at the water pump, the impellors might be partially corroded away, again causing the situation in city traffic. If that is ok, I would have the radiator boiled out, then if it still continued, I would go with a pusher e-fan (in addition to the oem fan)...since on a van especially, the engine is definitely sitting in a "cave".....on the ambulances, I know they install louvers in the hood to relieve heat....so this very well might be a design issue.

 

Have you performed a cooling system pressure test yet, checking for a possibly blown head gasket? This sounds very much like that to me. I'm assuming when changing t'stats you didn't notice any motor oil mixed in---wonder if there's coolant in the oil pan?

Hope its nothing serious!

 

Checking the resistance of the fan clutch tells you absolutely nothing. The only way to actually test a fan clutch is with a strobe tach, not a tool that most folks have handy.
At 22 years, I can almost guarantee the fan isn't moving enough air at idle and causing your overheating. The average life span of a fan clutch is 8-10 years.

Spray both sides of the radiator well with a detergent like Simple Green or Purple Power. Let it soak a few minutes them blast it out with your garden hose, preferably from the engine side.
If that doesn't help. replace the fan clutch with a Motorcraft or Hayden unit. Avoid the cheaper units from the chain parts stores, they typically don't last.

 

Thank you for your answer.
I am bringing the van to my mechanic and I am debating whether I should let him check it or since he has to change the termostat (I bought a Motorcraft) if I should just bring him a new Motorcraft clutch and water pump and have it replace at the same time so I don't have to go through this again later and pay another round of labor charges.
Also since the motor can be surging heavily at idle after being operated for a while (it will not do it in the first half hour) especially but not exclusively when driving in traffic and when it is hot. What do you think of JWA post that it could possibly be a blown head gasket? If not what could it be, I have worked on that check list:
Rough Idle – the Ultimate Guide
and was thinking air sensor, this is been going on for a long time, I had tunes up done and checked for leaks but my mechanic seems to have a hard time fixing this problem for good.

 

I certainly respect every response you have recieved, this is what I would recommend....
While it is true that a fan clutch that has resistance may in fact still be bad, is true, but typically more than not, if it has good heavy resistance, it's an indicator that it is still good. While it is a possibility that a leaking head gasket is an issue, I would say it is not a probability, if it is, it would be small enough to most likely be confirmed with a coolant test (for CO...which you can actually purchase at NAPA or other parts store for about $50).........if it's that small of a leak (confirmed), I would really consider a chemical sealant.....there are a couple of good ones on the market that have been around for about 10 years.....and while I know and will agree that the absolute correct procedure would be to replace the head gasket, machine the head and re-install, the (mechanic) costs is likely to be $500-$800....and for an engine thats say 1/2 worn out (mileage wise), a chemical sealant is worth a chance and are typically very effective on tiny leaks.

I don't think I would buy anything yet...and if there is a (good recommended) radiator shop close by (unless the mechanic you know really good will take care of you $ wise as well), I would let them take a look at it..typically Radiator are like a "specialty surgeon"- knowing systems and their specific issues, except they charge a little less than a typical mechanic and can also effect radiator repairs that are much cheaper than what most mechanics have to avail.

 

Thanks again for your help, it is well appreciated.
To resume, change termostat, check water pump, clean the radiator and boil out if necessary (I really gave it a thorough was when I changed the termostat a few months ago). And preferably visit a radiator shop rather than my mechanic.
Do you think the surging is related or unrelated to the cooling issue?
And proceed with coolant test if no changes or just do it for good measure.

 

I kinda doubt the surging is related.........
Yes definitely do a coolant test to CO and if all is good (Raditor shops have this kit as well), then let a radiator shop check it out...maybe even do a radiator boil out which is inexpensive and really cleans out what a flush cant...they can also do a flow test (Radiator shop) to check for obstructions...

 

So I brought the van to a radiator "specialist" that was an adventure by itself, anyway to make a long story short, the guy talked me into replacing the radiator I still had the same problem so the specialist reinstalled, after cleaning it out, the original one. I also had him change the thermostat with a new motorcraft one and still no difference. He tells me most likely there is a leak so I am taking the van in to my regular mechanic to perform a pressure test tomorrow.
I told the specialist about the chemical sealant and while he agrees the head gasket job would be expensive, he says the problem with the sealant is that it seals everything else too and creates new problems...? Any opinion and advice on what sealant to use if I have to? Thanks.

 

Get the results of the pressure test first----in fact this step should have been done a long long time ago in your process F90E350, unless I've missed seeing where its already done?

No offense but that radiator shop doesn't sound like the best around----are there any others close to you?

I myself tend to shy away from the stop leak type products but in your case it might be cost effective. I'm pretty much just guessing but your engine's inner cooling passages will be sufficiently sized so as to not be blocked by the sealant. Your existing radiator might be affected, depending how it flows now but that's something you'll have to visually monitor at first.

Still hoping this turns out to be a cheap and easy fix!

 

I agree....sounds like the radiator guy was maybe not the "best" radiator guy so to speak but was honest with the radiator dealings.....Thats very good that he boiled out the radiator (and pressure checking it comes as part of the boil out) and replaced the thermostat so you know they are absolutely good...one less question a mechanic has to address....and with a system test...the mechanic can now focus on finding the issue.

I think you are right on track!

 

sounds to me to be a bad water pump.does not sound like a bad head gasket