how cold engine is bad?

Running with a colder than normal engine will kill your gas mileage, and probably cause your oil to become contaminated more quickly due to a rich air-fuel mixture.

Are you sure you used the correct replacement thermostat, and that the replacement is not defective?

You could test your T-Stats by putting them in a pot of water, bring it to the boil, and see if they open.

Yes driving with a cold engine is best avoided.

That's a dead givaway that it's a bad thermostat. I've seen poor quality ones before. Make sure you get the OEM brand. On your first original post

you said the problem happened after you changed thewater pump. Did you mention seeing coolant flow?

Poor performance, catalytic damage from rich mixture, gas in oil like Hancock mentioned and best avoided at high speeds or long term driving. Ind

You sure could be describing air in the system.

Some vehicles are real buggers to get the air out. I would be checking the run of the hoses to see if any are above the fluid level in the rad. If they are, they are prone to air lock.

Mike

86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 88 Cherokee 235 BFG AT's

YKP wrote:

Seems to me this is by far the best explanation offered.

So, to sum up, you've put two thermostats in the engine and it seems to experience wide temp swings but stays cold when you pull the t-stat out?

Are you sure you are putting the t-stat in the right direction? Wide temp swings / overheating with a new stat are often a sign that it is installed backward. Most applications require the copper cylinder to be on the engine block side of the housing, not facing out toward the radiator.

Corey

Hi, Young. I have a "hot rod", really a stock Chevy Blazer with a stock Camaro engine, that is a quite popular swap amongst Chevy enthusiasts. There are many articles, products, theories, and other materials concerning keeping the system cool enough to drive and yet hot enough for safety, wear, and warmth in winter driving. After thorough research, I decided that what it needed was just a little help with a constant "seepage" of cold water into the engine. Guess what I did. I drilled several holes--wrote down size and # of them, and drew a schematic all of my first trial. Lucky in a major sense, yet unlucky for the sake of research for optimal size and number, it worked to so near perfection that I quit right there. Wife even drives it to school where she teaches when I need to get her car cleaned/seviced. Hundreds and even thousands of dolars have been spent on trying just to make this combo streetable, and all it took was 'your' simple technique. Sounds as if you may have a tad too much constant flow--which can be rectified by less holes or smaller, or both, to allow a tad less constant or "free" flow. Congrats on finding a solution. And remember, the engine really needs to reach a certain operating temperature for longevity as well as adequate heater operation. So, with a tad more experimenting, you may wish to mod another t'stat or two w/different parameters. They are certainly cheaper than engines! HTH & good luck. sdlomi

snipped-for-privacy@excite.com (Corey872) wrote in news: snipped-for-privacy@posting.google.com:

Yes, I put them (yes, two t-stats) on the right direction.

Young.

"sdlomi" wrote in news: snipped-for-privacy@corp.supernews.com:

Hello there,

You said you wrote down size and # of the holes. Do you still have information? Like you said, I can tried with different configuration. But this S-10 has t-stat on bad location. It is giving me hard time to get it out and back. So if you can give more hints, I may reduce my work hours. I am also thinking of trying with low temp. t-stat. the 195F is the default. But I may try with 180F.

This car has caused many problems since I bought it. And I am thinking of buying new car next year. Because of that, I don't think that it is worth of spending thousand dollars to fix this problem if there is a trick.

Thank you,

Young.

"Robert Hancock" wrote in news:odTAb.595308 $6C4.373211@pd7tw1no:

Thank you for the reply.

Yes, I tested those two t-stats with boiled water and both of them opened and closed when they were in the air. One was a dealer part and another one was bought at local auto part store.

Young.

"Indian Summer" wrote in news: snipped-for-privacy@news.bubbanews.com:

I like the website

Pretty neat when I need to refer a long URL. =)

Thank you,

Young.

Air locks should be suggested more often for overheating problems. I had my radiator repaired and the mechanic parked the car on a hill outside while he carefully filled the system with fluid so there wasn't a single bubble of air in it. I've never seen anyone else bother to do that. It probably explains the overheating of my Chev 350 that had very long radiator hoses. I had a reconditioned clean engine, new water pump, new extra large radiator, a large 8-blade fan fixed to the engine, and two large electric fans. No expert could fix the overheating.

wrote

Probably because it's not necessary if you know what you are doing. I've never parked a vehicle on a hill in order to bleed the air out of the cooling system. And I can't remember the last time I had any trouble getting the air out any cooling system that I've worked on.

Geez, that almost sounds like it might have been Dardwin bleeding the cooling system!

Ian

I drilled, like, 10 holes evenly spaced @ 1/8 inch diameter. If I were you, I'd drill one with about half the total area as your first one, and compare from there. sdlomi