180F Thermostat in 88 Suburban

Won't run "rich" and flunk emissions, but will run "richer" and affect fuel economy. Stick with 195* (which was OE).

Doc

You will be just fine with an 180F thermostat. The truck goes into closed loop around 150-165F so you will also have no problems with the emissions. I have been running an 180F thermostat in my 91 suburban for 10 yrs and have had no problems. Anyway you can go to the colder thermostat and it will hover a little more then one quarter of the temp gauge, if I remember correctly the first line (0/4) is 100F the second (1/4) is ~175-180F and the third (2/4) is the middle of the gauge (probable where it sits now). Make sure you put in a high performance thermostat they flow more coolant then the normal and if you tow you will see the truck run much cooler. I would also get a real good gasket from the dealer or a fel-pro gasket. The intake and the neck are aluminum but for some reason they

expand at different rates and the cheap gaskets will last less then a year before they start to leak. As I always tell people this is a good time to check you hoses and belts. If they are spongy or soft change them and if the belt shows any cracks on the inside (side against the pulley) change it.

good luck, mark

Slower aging of rubber and plastic parts. Best I recall when engine temps went up a lot of underhood polymers had to be changed to take the extra heat. Polymer aging tends to go up exponentially with temperature.

You're right to question reduced efficiency in exchange for intangible benefits. How much will mileage be reduced? During combustion gas temperatures increase about 1000F. Will dropping the starting point by

10F make a significant difference? Perhaps better atomization/vaporization and more complete burn when starting 10F higher?

-RC

R.Clarke spam snipped-for-privacy@BlocKmindspring.com RTP, NC, USA

It currently sits a tad above 1/4. Don't know what the previous owner ran.

Here's the reading on my gauge-

0/4 100F 1/4 no number 2/4 210F 3/4 no number 4/4 260F

Twice the jump between 0/4-2/4 compared to 2/4-4/4. Hard to say what that 1/4 mark is in degF.

-RC

R.Clarke spam snipped-for-privacy@BlocKmindspring.com RTP, NC, USA

Hoses are way up on my long list of rehab action items for this truck. It looks like nothing was done to this truck for the last 16 years (90k miles) but oil and plugs. I've got about 50+ things to do before I feel safe taking this Sub on a long trip.

One of the heater hoses has a swaged metal pipe attached. Looks like a dealer item.

-RC R.Clarke spam snipped-for-privacy@BlocKmindspring.com RTP, NC, USA

Well it will increase the oil change intervals to 70,000 miles, it will add

600 hp and it will create an almost supernatural attraction to you that only works on redheads and blonds......

In my case I towed a trailer and I would see the temp peak up to almost over heat under normal towing (during the summer), which with the stock stat is less then 80 deg's hotter. So in my case it fixed my temp issue. I prefer to run gas engines cool (160-180F) and diesels hot (195-210F). So it is one of those things you caulk up to personal preference. As far as fuel economy I feel this is a fallacy, as long as you are allowing the system into closed loop the *15 deg difference* will produce little (if any) change in mileage. Now, if it was a customers car then I would put in the OE temp stat but when the person asks if it will cause issues with the ECM and it isn't an OBDII system, then I will tell him it can be done w/o problems. In my case I had not seen *any* change in mileage what so ever. So...everything perceived is based on who is perceiving it...

mark

Right the supply hose from the back side of the intake is a formed metal piece (metal fitting, pipe to a hose). I suspect you can go to an autoparts store and get a nipple and replace the whole thing. Make sure you use long hoses. The long hoses will be less likely to transmit the vibration from the engine to the heater core. The core is fairly easily to replace just take off the glove box door (bolts across the bottom) and the four bolts from the engine side (one on each corner, you will have to dig off the tar to get to them) and the whole box will come down and wiggle out onto the cab floor. Will take about 2 hrs and save you about $300....

mark

Yea I once got a service manager to admit that the gauges are about as accurate as sticking in your finger and picking a number out of thin air. I guess that is why ford does not ever put number on their gauges... But a tad above a quarter is where I sit and when towing (and hot summer days) it will sit a little closer to the middle of the gauge. According to a thermocouple I used to diagnose a temp issue the quarter mark is about

176deg but I suspect that will vary from sender to sender...

mark

Nope. Beenn running a 180 in my 1988 GM C1500 and emissions and fuel milage are the same as with a 195 stat.

The EPA net nannies here seem to believe otherwise

So you are saying that with a 195 degree t/stat and towing...you were close to "overheating", but you put in a 180 degree t/stat, and now that "magically" stops the temp guage from going up higher when you are towing? I seriously doubt that. I would make the same argument that you make, a stat that opens 15 degrees cooler will do nothing for any "perceived" overheating problem while towing. If the cooling system can't control your temp while towing with a 195, it won't be able to control a 180 either. But you believe what you want.

Ian

It's really rather pathetic how many "old wives tales" there appears to be about cooling systems on these newsgroups. "I think", "I believe", "some guy I know says", "it seemed to work for me".... basically anything, but real facts, and/or a half assed understanding of how cooling systems work!

Oh well, such is the life and times of the newsgroup "DIYer's" "I like my gas engines to run cool, and my diesels to run hot". Ok, whatever, buddy.

Ian

systems......

Mike taught me that my truck will decide what temperature it wants to run at all by itself, so I just yanked the t-stat and let ol' Chelsea make up her own mind how hot or cold she wants to run! I'm thinkin' that she knows how rich or lean to run all by herself as well and plan to remove my 02 sensor next weekend! That plug sittin' right in the middle of the exhaust collector has GOT to be blocking some flow.

Doc

LOL.... Oh well, job security I guess. Bob

That's right... And if I were you I'd forget the fuel injectors and all the related bullshit as well. Just plumb the fuel line direct to the intake plenum and let her drink as much as she wants. You won't likely notice a difference in the fuel mileage and Chelsea will be a "happy girl" lol.... I can't believe the time engineers waste on such things as deciding a proper operating temp or fuel mixture. Bob

You forgot to mention removing the fan shroud for "improved" cooling.

Rita

No your are right if the system is overloaded no matter what you do besides going to a larger radiator will fix the problem. In my case it was the fact that the OE thermostat did not flow enough coolant and by the time it fully opened it was almost to 3/4 of the gauge. Now I do see what you are getting at by no means is 230 deg overheating when the gauge tops out at 260 but I prefer it to not be more then 3/4 max. So once again I am telling you based on what this truck did when it was 2 yrd old. So *in my case* the 180F thermostat I installed did fix the problem. The 15 deg cooler temp meant when it fully opened the normal towing temp was about where I wanted it (~200deg).

He he he he he he...................