thermostat... radiator fan new clutch.. but...

[la nomade]

just arrived in nova scotia....recently i replaced the fan clutch....temperature normally goes up quite fast to 190...200.....and should be ok if going up a bit but not over 240 when the fan kicks in....that is how it used to be...the fan rarely came on roaring only when going up a hill,or stuck in traffic,well the fan went on and off during my intire trip as soon as temp.reached 190 or 200...it was raining and cool....does that mean that while changing the fan clutch somehow the thermostat got all ......up,and out of wack...plus where is it???will have to take it to a gm garage somewhere,it was so unpleasant and stressfull to drive with this fans going on and of every 3 or 4 minutes.i need some ideas and input on this problem so i can tell the mechanic what you all suggested the cause of this is?????once more HELP....

[RickDavis]

If this is the typical fan clutch on trucks etc . The clutch is engaged by a bimetal spring in the hub itself which senses the air temperature coming through the radiator. It should not have anything to do with the engine thermostat.
Sounds like the new one is just set up to operate at a lower temperature.
The factory fan clutch on my Dodge truck would come in so gently I usually wasn't aware of it. The replacement I put on at 500k miles comes on more positively and at a slightly lower temp.
I may be off base, but that is what it sounds like

[dadstoy]

I just recently went though this exact problem. Last year I had the radiator recored. This is a must if you have overheating problems, but it is not the issue you are having. You just want to make sure you are starting with a good radiator.

Before I had the radiator core rebuilt, I had installed a 180 degree thermostat, which I later learned was a mistake and this solves nothing if one is overheating. After the new radiator core I also put in a new fan clutch. This was the last purchase that I will ever make at Autozone!

With the radiator in great shape, new hoses, belts, water pump, thermostat and fan clutch, I did a 800 mile trip. The fan clutch engaged fully for 70 seconds then off for 70 seconds...this was constant for the entire trip and it drove us crazy!!! Radiator temp fluctuated between 170-180.

After that trip, I took out the Autozone fan clutch and beat it to death with a very large hammer! Then I got a real fan clutch from Napa along with the proper 195 degree thermostat. The next day I did a 1000 mile trip from Redding Calif to Coos Bay Oregon and back which is mostly mountain driving with many 6 percent grades that go on for 6-8 miles each.

The fan clutch worked as it should! I seem to keep teaching myself this lesson over and over and it doesn't sink in for me...don't buy the crap parts at the Autozone type stores.

After doing much research I found out that the autozone and Napa parts are made by the same company, but the Autozone fan clutch is made in China and the Napa one is made in the US. You may have also gotten a lighter duty fan clutch that has a lower degree thermostat on it so it is always coming on because your engine is always running at a higher temp. I also learned that some manufactures lowered the temp that the fan will engage on some of their parts...they thought this would be a good thing, the real experts say it is not. the fan clutch must also be matched to the radiator thermostat.

The thermostat is on the front of the clutch. It is a coil spring. Some are soldered at both ends of the coil and some are not.

Bottom line for me was to install the correct 195 degree radiator thermostat and to get the quality heavy duty fan clutch from Napa.

[la nomade]

i feel much better now....my new clutch came from car Quest....now,since i am in canada i wonder where to get a new clutch which will not do the same thing...will tell the GM mechanic about what you mentioned...i am relieved that others had the same problem...and yes it almost drove me completely crazy..so i MUST have this fixed before i go back to ny mid september...Thank you so much M

[bkahler]

Over the years we've had poor luck trying to find good replacement fan clutches for our vehicles. I'm not sure if they are making them cheaper, stored them laying down instead of upright or if we've just had bad luck period.

My only suggestion would be to buy the best one you can. How do you find the best one? I'm sorry to say I don't have a clue.

If you do find the correct one please post the part number and where you bought it from.

Brad

[ScrapIrony-2]

We had our thermostat replaced about 3 years ago, set at 180, and until I returned the beast to Texas in June from the cool climate of AZ, I had no problems...BUT, the return trip required stopping when the gauge showed 220, then a standstill until it cooled down...not a fun or fast way to travel, but I usually don't drive more than 100 miles a day. A hot engine pretty much stops your starter from engaging until you cool down...an inherent disease of the doghouse 454.

[ScrapIrony-2]

By the way, while I was toasting in Tucson, I had the right exhaust manifold replaced..well, repaired, as mine was stainless steel, and the one shipped from Texas was cast iron... the guy who did the work was good, saved me quite a few bucks, and recommended that I have 'my' mechanic install orifice inhibitors. he told me that the air intakes for the 454 'afterburner' caused too much heat, but reducing this airflow would solve my overheating. he did mention that this would be a California no-go for emission standards.
He was in business doing exhausts, mufflers, and manifolds for 40 years, sold his business, and then had to repossess it..builds race cars in his spare time, and the one I had the privilege of inspecting was truly impressive...from the front tanks and nitrous boosters to the reinforced frame..So, as soon as I find a reliable 'my' mechanic, i'll have the work done...

[la nomade]

the Gm garege here in nova scotia could not figure out what fan clutch to replace mine with,they get them from Nappa...So i did what i should have done in the first place,called Brian hawtin at colonial airtstr.in New Jersey...he is getting me and mailing me the right part,a fan c lutch like the original one ..plus mailing me the city water hook up part that is badly leaking and is craqued in places...no one in nov.scotia or even new brunswich had it or could not get it!!!!

Brian has in the past helped me with all my retoration,given me good advise and got me all good new parts,,,,his tel is 1 800 265 9019 ext 108...


email. hinopartslgmail.com

will let you know serial n etc when i get it..........and the GM garage will send a guy to put it in for me so i do not have to move my rig,besides thy have no spave for me to park there,i am to large a motor home for them...it will all work out for the best and will peacefully drive home in september without this roaring going on every few minutes....m

[la nomade]

sorry for all the typos,was using my ipad ,my lap top having had a brake down for a while

[dadstoy]

Originally Posted by la nomade

sorry for all the typos,was using my ipad ,my lap top having had a brake down for a while

You have that same problem that I have with the iPad!

[la nomade]

it has arrived this morning.....all the way from new jersey to nova scotia....here is the info: made in USA
GMSPO....,, Part number 88961767
6812797
AND ALSO 15111.......
It cost $242.88
what a relief to know i will drive home without this thing going on every few minutes with this terrible noise.I hope this info will be useful to some of you.M

[dadstoy]

Originally Posted by la nomade

it has arrived this morning.....all the way from new jersey to nova scotia....here is the info: made in USA
GMSPO....,, Part number 88961767
6812797
AND ALSO 15111.......
It cost $242.88
what a relief to know i will drive home without this thing going on every few minutes with this terrible noise.I hope this info will be useful to some of you.M

La nomade, did you get your new fan clutch installed? Did it solve the problem? I'm not happy with the second one I put in from Napa. As I had mentioned, the Autozone part did the same as yours, constantly on and off and the Napa part is 50% engaged all the time. I don't think I'm finding the right part for the Motorhome application and I'm becoming very disappointed

[la nomade]

yes i did replace it and gave you the info as to the new one i got and installed...drove home with no problem,it works fine...you have to get the part from a chevy GM dealer.....i was very relieved that it actually solved the proble...good luck M

[bkahler]

I wonder if this is a true GM part or a clone listed with the same part #.

fan clutch

Brad

[r carl]

Originally Posted by bkahler

I wonder if this is a true GM part or a clone listed with the same part #.

fan clutch

Brad

Its real.

[dadstoy]

When I search for 88961767, it always comes up as an AC Delco part, so I think it is a GM part number. I also believe 8896167 has been replaced by part number 154949.

[PeterH-350LE]

I need some input on my fan clutch. How do you know if a fan clutch is bad?
On my previous MH it would engage when I slowed down and disengage when I speed up, like clockwork. On this 345 the engine seems to roar at all times, it never changes. I never heard the clutch engage or disengage. With a cold engine it will not spin freely, it just moves an inch or so if i try to spin it by hand.

[bkahler]

Originally Posted by PeterH-87MH

I need some input on my fan clutch. How do you know if a fan clutch is bad?
On my previous MH it would engage when I slowed down and disengage when I speed up, like clockwork. On this 345 the engine seems to roar at all times, it never changes. I never heard the clutch engage or disengage. With a cold engine it will not spin freely, it just moves an inch or so if i try to spin it by hand.

Peter, sure sounds to me like your fan clutch is no good. Your description of your old motorhome pretty much matches how our 310 operates.

I think you probably should check into getting one of the GM brand clutches and install it.

Brad