I got a Motocraft 180* thermostat to replace the stock one, and I noticed that the new thermostat doesn't have a bleeder valve on the top like the stock one had. Is this going to cause any problems? I had a suggestion to drill a 1/8" hole in the new one (where the old thermo had a bleeder) so air can escape, is this okay? Thanks!
thermostat question
- Thread starter 1992blkGT
- Start date
maverick0716
Founding Member
Michael Yount
Mustang Master
Be sure to drill/position the hole at 12 o'clock when the t'stat is installed. The closer the hole is to the top of the t'stat housing, the more easily air can pass out of the system.
Michael Yount
Mustang Master
leakyfaucet - the purpose for the hole seemed obvious from the other posts in the thread...when filling the system with coolant it allows air to get past the t'stat reducing air pockets in the system.
"The closer the hole is to the top of the t'stat housing, the more easily air can pass out of the system."
"I had a suggestion to drill a 1/8" hole in the new one (where the old thermo had a bleeder) so air can escape"
"The closer the hole is to the top of the t'stat housing, the more easily air can pass out of the system."
"I had a suggestion to drill a 1/8" hole in the new one (where the old thermo had a bleeder) so air can escape"
Michael Yount
Mustang Master
When you fill the system, coolant comes into the bottom of the block through the lower water pump hose. In order for it to rise in the block/heads, the air in the block and heads has to go somewhere - easiest path would be for it to be able to get past the t'stat and out the upper hose to the radiator - where it can escape the system. The little bleeder with the jiggly-valve in the t'stat is there for that reason, but some less expensive t'stats don't have them. Drilling a small hole instead serves the same purpose.
IndyBlk5.0
New Member
yeah im going to probably drill a small hole in my new 180 t stat i put in.
where do i drill this hole? how large of a hole? need details please... Thank you
where do i drill this hole? how large of a hole? need details please... Thank you
Michael Yount
Mustang Master
i agree with Mr.Yount. you could match it up to your old stat for an idea of where to drill, if you want. i chose not to.
a really good stat, like a Mr Gasket (my humble opinion), is a few dollars more and leagues above the parts store variety (living in 110* temps, im anal about cooling).
some cars have bleed screws on the top of the head to crack to bleed. we are not so lucky.
good luck.
a really good stat, like a Mr Gasket (my humble opinion), is a few dollars more and leagues above the parts store variety (living in 110* temps, im anal about cooling).
some cars have bleed screws on the top of the head to crack to bleed. we are not so lucky.
good luck.
i chose the Mr G because it is balanced, opens more quickly and fully sooner than parts store stats, as well as having the bleed hole. after reading the whole thread, i forgot you had an oem unit. i have no experience with those, but im sure they are a good unit. i was quite impressed with the Mr. G, and that was my point (especially when compared to a parts store pot metal unit). strange then, that ford omits the bleed hole.
like i said, hold the two up next to eachother and mimic the placement of the bleed hole on the old unit.
again, i did not mean to offend. good luck.
like i said, hold the two up next to eachother and mimic the placement of the bleed hole on the old unit.
again, i did not mean to offend. good luck.
Michael Yount
Mustang Master
Well I'll step out on a limb here - Motorcraft, Ford, whatever, like so many other companies use many 3rd party suppliers to produce parts for them. I don't know who's making the t'stats for them, but if they don't come with the jiggly valve, it's an inferior product. These days more than ever you can't just look at the brand - you must look at the product and the design. In my opinion - a good/proper replacement t'stat comes with the jiggle valve; it comes with a gasket that's got a peel off-adhesive on one side to hold the t'stat in place which significantly reduces the chance of leaks during install (keeps it from sliding down and partially blocking the housing/manifold seal); and it comes with a slightly irregular shape circumferentially -- look carefully at a stock housing and you'll see the indentation for the t'stat is mis-shaped; this allows the t'stat only to be installed with the jiggly valve in the noon position.
I also bought a thermostat with no bleeder hole. At the time I didn't realize how important it is. Anyway when I filled up my coolant, the first start the engine got quite hot. Reached almost 220 degrees before kicking in, and this was with a 180 thermostat. Finally thermostat opened, and everything was fine. Doesn't get much hotter than 180 now. Next time the coolant needs to be drained or any chance I get I'm going to swap it for a better quality one.
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