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DMAX fan cure for overheating ???

S

Steve93mustanglx

Diesel fanatic!
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Location
Midlothian, VA
looking at SS Diesel's DMAX fan on fleebay... wondering if it would help my engine heating up at idle. These 100 degree days are not kind to a 6.5 with the a/c on and in traffic.
 
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Steve I'd be very cautious about SSDs claim, they have been known to embellish performance ratings, rather than water GWs thread with your specific questions I've moved this to a thread of it's own.
 
I will say, my Sub came with a bunch of SSDiesel parts on it when I bought it (the PO lived 15min away from their shop) and it has the upgraded dmax fan/hd clutch and I cant get the truck to go over 180'F no mater how hard you push it or how hot it is. I checked the sender and changed the T-stats with no change, so I will say that some of their parts arent to bad. I wish that my truck had that problem since it likes to run 210'F any time it gets pushed.
 
I've still got his fan clutch out in the shop, and the fan from it is currently in front of my DMAX. I found it to work really well, and it kept the engine temps even with my blown head gaskets cool all the time.
 
Thanks Tim (et al). I think I have found my next mod! 6 bladed fan is fine on 85 degree days. I have a new stock pump, thermostat, fluid, all new hoses, cleaned radiator just 1 year ago (at rad shop) and with my pressure washer. But put the a/c on, or hell leave it off... it wont keep up on a 100 degree day. Keeps climbing at idle. Scares the pee out of me.
 
Steve something not rite, with your setup which is also partly why I wanted to have this in it's own thread so we could explore, AC on or off on both my 6.5s in same or hotter weather as you are seeing and no overheat.

You used a pressure washer ??? are you sure your rad/ac core fins aren't folded over or the outside stuff got pushed deep into the core ??
 
It was close to 100 here yesterday & I was romping on mine on the expressway on my 50 mile ride home from work. My OEM temp gauge never went over 200F. The EGT's were running up to 950 & for the most part settled in at 600~650F with my A/C on & no load. Had me wondering what them temps would have been if I would have had 6K pounds hitched up & strapped to it's arse...:confused:

As far as I know my entire cooling system is stock OEM...might be time for me to look at the Dmax fan if I'm gonna attempt to tow anything with the A/C on in 100+ heat :rolleyes5:
 
Remember- I am saying this is at idle, typically a/c on. Driving around in 100 degree heat with no probs at all. Stop in traffic for 10 minutes or so, get out to load trailer and leave it running, it usually does go over 210.

Tim- The radiator was flow tested and chemically cleaned by a reputable shop here. As it has plastic end caps, it wasnt rodded. But you can look in and it looks fine. Like others, I pressure washed it to damned near death! Since removal last August I periodically pressure wash through grille (whenever I have the washer out for odd jobs) just cuz.

Driving through town and on highway though, never crosses 210 and basically stays at 195.

Was thinking the DMAX fan might be worthwhile for the idling issue?

Edit: used a radiator comb to straighten fins too. ??
 
Pressure washing is a huge NO-NO it bends the fins over and you can't flow air correctly, which is why I think your at idle issue is happening, when driving @ highway speeds you overcome the bent fins with force of tons of forced air flow, at idle you are counting on the ability of the 6 bladed fan for pulling what it can through the stack on it's own.

I'd go junk yarding to see if you can't find a 9 blade steel or composite bolt on fan

If you want to periodic clean it, garden hose it from back side of AC core, and back side of the rad core, I like to use the hot water heater drain valve off the house on my garden hose with simple green or purple power (watch your paint) to do the periodic maintenance back flushing
 
I soaked the radiator first with a cleaning agent, then garden hose water. Still had some crud in there, so I used the pressure washer. But I didnt have that problem (bended fins). I combed them b4 and after... so they are fine.

To be clear- this thing was cooling WAAAAAAAAAAAY better after all this. In fact I wondered for a while if it would ever get to 195!

Now though I have finally gotten my A/C fixed (see other threads). It is still fine on highway, and normal city driving. But get in a traffic jam or leave it idling for 10-15 min, it climbs.

This is what I am looking at. http://cgi.ebay.com/ebaymotors/ws/e...0444144212&viewitem=&sspagename=STRK:MEWAX:IT

Junk yards have NO Dmax or even 95-up trucks around here. Nuts!

I'm not trying to buy hype whatsoever. I do believe a 9 blade fan has got to be better than my stocker. Any cheaper routes with good results I am ALL for them!
 
Steve93mustanglx said:
Remember- I am saying this is at idle, typically a/c on. Driving around in 100 degree heat with no probs at all. Stop in traffic for 10 minutes or so, get out to load trailer and leave it running, it usually does go over 210.
Click to expand...

Sounds like clutch is going out - at idle, it's slipping,
and truck heats up. Start moving, and you are forcing
air thru the radiator, temp comes down
 
Get a HAyden severe Duty Clutch. You clutch is most likely shot. 6.5s or any diesel for that matter don't run hot at idle, they cool down. Somehting is wrong with yours. You could swap out the waterpump to one off a 2000 and change to a center nut clutch and fan. The stock 95 WP doesn't flow that well either although that is generally an issue towing not idling.
 
If you decide to get a DMax fan get it from Rockauto. The 9 blade composite fan is only just over $50 plus shipping. The fan has to bolt to a clutch with a 4 bolt pattern. The older 6 bolt pattern won't work. I think your stock set up will be like mine (94) where the clutch bolts to the water pump with 4 bolts and 6 bolts to the stock fan. There is a severe duty clutch available that bolts to a 4 bolt water pump hub (since your WP is new) and has a 4 bolt fan hub (this is what I did). If my memory is correct it is for a 97 model year.

I don't know what kind of price SS has on their set, but check out other suppliers for the severe duty clutch. I got mine locally for about $180. I just checked Rockauto and they have a severe duty reverse rotation clutch for $162 plus shipping.

Don
 
Dmax fan works it's what I have, I have Walt/SSD issues in general my apology to the crowd, definitely check out Rock Auto.

Kenny's suggestion to upgrade to newer pump style is a good one, we just did this on his recently, older style will be harder to support if yours goes again later, and you might be forced into a newer one at a higher price and also be in a "have to situation" that won't allow the luxury of shopping around for best price.

So IMO you might as well go ahead and bite the bullet now and "modernize" yours. Buy the pieces and parts as you can afford them, since you are still able to get by with what you have now.
 
Start out with fixing the problem. You already cleaned/fixed the radiator. (A plugged radiator for airflow will cause heating at idle.)

Test the fan clutch.

Your OEM 6 bolt clutch will NOT work with any newer 4 bolt fan.

Cheapest:
New 6 bolt fan clutch. Not recommended.

Better:
Autozone for a Hayden four bolt fan clutch, 1998 year, and the dealer or rock auto for a 2001 Duramax fan. (Dealer wholesale ~$70.00 or ~$110 list. Figure shipping for Rock Auto...) My dealer had the Duramax clutch in stock vs. ordering the 9 blade steel fan. The 21" fan is lighter vs. the lawnmower blade steel fan.

Better still:
4 stud HO water pump to the 4 bolt fan

Most expensive:
"Thread on" HO water pump and fan clutch with dmax fan.

You may get better balanced flow with the Heath diesel recommended HO thread on pump, but, the 4 bolt stuff will keep you below 210 towing heavy. ESP with a lower t-stat and lower fan clutch. Not necessary for non towing lighter duty use.

With a lower 180 t-stat (single stat - dual stats not necessary.) I loved the low temp Kennedy Diesel fan clutch because it would be able to kick on before going over 210 hitting a hill at WOT. It would hang in and run a lot, but, I never had a temp problem with it. It would kick out when things got cooled down - but not until then.
 
Exhaust?

My 96 would run up to 210 under its own weight on a 3% grade on warm or cold days. This was with the stock pump, fan, clutch and exhaust. On 635's suggestion, I put in a 4" kit with new cross over and immediately after that the truck never got past 200 no matter what I drove up or loaded on and believe, me, I tried. Then there was the fun meter...that got high.

You've got a lot of goodies in your signature block so it would surprise me if you didn't have the exhaust upgrade howver, I didn't see it listed.

Then too, it may help someone else to so I thought it should be mentioned.

PCM reflash and the temp rarely gets over 195.

Heath HD cooling upgrade installed this spring and it is hard pressed to get TO 195.
 
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John Kennedy sells a LOWER Temp fan clutch that is actually a lower engage temp (200F engine temp)

Along with the Dmax plastic fan will keep the 6.5 real cool.

The 6.5 stock fan clutch will not engage until nearly 230F engine temp on many 6.5's

The reason this all came about is due to a major FUBAR by GM.
Early on, (back in the 80's) many whiners in the motoring public would scream to high heaven when the fan came on and roared like hell.

This could happen in traffic with the AC on or pulling a grade in the summer heat.

GM decided (BAD PLAN) to raise the engagment temp on the clutch and by doing so rewarded us with engines that overheat.

The early DMax's would overheat too, due to the same F'UP

The fix was a reacalibrated fan clutch. (LOWER TEMP)

Once the coolant temps get to about 220F or so on a hot day, its tough to get them back down.

The cooling system (Radiator) is too small with zero extra room in ability to reject heat.

With the Kennedy Fan clutch and DMAX fan, the system will engage, roar like hell and keep the thing cool.

On a warm/hot day the fan will come on real good in slow traffic and keep the temps below 200F. On hard pull, same thing.

Having a good radiator that can reject the heat is an absolute must.

Install a 180F stat too. These start to open at 180f and are fully open at 190F

The extra 10F really helps out in getting a leg up on the heat. I know that manym say that the engines run more efficiently at 190-195 Guess what, your never gonna see or feel it.

The lower temps mean less thermal stress on the engine block, heads and such.

The main reason for the higher temp stat is a slight reduction in the emission levels. BIG WHOOPI

If the radiator was 20% larger, most all of the heat related issues would not exist. Problem is that there is no room in the front of the truck.

I have seen a fes off roader install an extra radiator in the bed with an electric fan system

Good luck with your heat.

The moral of this story is to not let the whining of folks who know little to nothing about things, influence the design. :nono:

Had a fellow come to see me back about 88 and complain bitterly that his tranny was slipping when the truck was pulling hard in the mountains (YUP, just the fan clutch coming on)

He argued up and down that the engine was "racing and the thing was slipping. I wires in a tach as a temporary and took him out and showed him.

He still swore that it was not right. We swapped out the good fan clutch, the noise went away and he was Happy, until it got hot. :eek:


Missy
 
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Paveltolz- it's in there! (Pinnacle) Or maybe it's just Jardine now. Not sure, but it's snuggled in my sig!

Thanks for the replies- I will re-read tomorrow and prolly have a question or two. Sure hate to dump my new water pump... but I want this thing rock solid reliable (as a 6.5 can be)
 
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