Radiator day from hexx

[sootie007]

Well my radiator at 99k developed the hairline cracks on the drivers side...luckily auto zone had one....what a pain to get to the bolts to get it in and out ...I also decided to do the water pump - no problem pretty straight forward BUT then I decided to swap in a new thermostat ....I immediately snapped the lower housing bolt off in the block ...45 minutes later with vice grips it snapped off again flush at the block ITS SEIZED BIG TIME .....probably due to Vermont road salts early in its life ......TOMORROW I am headed to home depot to buy an easy out and angle drill ...wish me luck this *****......J

 

[sootie007]

I had to drill the stump out but its all in there now....13hrs , water pump,radiator,thermostat around 300 dollars ........J

 

[sootie007]

Check engine light came on today 10 minutes into my morning commute ...code

P1281 "The engine is staying cold too long - check thermostat" .....

MY FAULT !!!! Being an old hot rodder I decided to help the thermostat out a little when I replaced it and drill qty 4 1/4 holes in it. ON old cars this helps flow at idle and can buy you a few degrees at the gauge - here in Florida every bit helps ...so basically I ruined a $25 dollar brand new thermostat I just put in the Jeep aaaaarrrrgh damx computers ...ha ha ....J

 

[ridenby]

I thought same till I read somewhere that Libby set up allows % water flow at idle and cold.

 

[sootie007]

Just for the heck of it I put my factory thermostat and a high performance Mr. Gasket 180 stat I had laying around in a pot of boiling water ...my factory stat was pretty much shot as it would only max out and open 1/8th inch ????? My dash temp gage always read at the 50% mark indicating all was well ...I guess thats why they call them idiot lights .......the hi po stat as you can see opens up a nice 1/2 inch-obviously will flow better ....I am going to put the 180 hi po one in with the factory stat o' ring and see if it can sneak by the computer without tripping the 1281 code . The hi po stat should work as its only 1mm in diameter smaller than the factory stat at 54mm vs 55 mm and the o' ring fits. It doesnt have the tiny checkball thing in it but I will drill a 16th inch hole in the hi po to mimic that functionality of the stocker....I dont know what the criteria is for throwing the 1281 check thermostat code but this may sneak by .......ps factory stat is stamped 195 degrees.

"MR GASKET P/N 4364 BALANCED THERMOSTAT GM/FORD/AMC 180 F" J

 

[ridenby]

Does the gauge show different position?

 

[sootie007]

Riden not sure I know what you mean but my gage is working ....it starts at totally cold and goes to the 50% mark on temp which I dont see how it could have been ok with the factory stat only opening 1/8th inch ....I have heard others state they have had boiling vapor coming from their overflow tank yet the gage still shows everything is o.k. so you must really have to be hot for things to show at the factory gage..........hope I answered your question......stat goes in tomorrow ....J

 

[ridenby]

Yeah,I wondered if 50% mark on gauge was like the factory universal position. That is where mine hangs out at,even when it ought to be showing high temp,IMO. Guess if gauge does go up its trouble time. Thanks,Dick

 

[sootie007]

Well the 180 degree hi flow stat is in and hasnt thrown the 1281 too cold OBD code yet . Whats funny is the dash gage is in the exact same position with the 180 hi flow stat in vs the factory 195 degree stat. So there must not be much resolution in that factory gage as others have stated. I have an infrared gun at work I will bring home and shoot some engine temps just for the heck of it. But it looks like this stat is a workable alternative to the 195 stat. that wont turn on the check engine light and throw a code. If it throws a code I will be sure to update this thread so nobody wastes any money. J

 

[sootie007]

It throws the engine is too cold - thermostat code intermittently - so unfortunately running a colder stat trips your trouble light...I can get away with it for months at a time and then it trips on a cold morning or on a rainey morning ......J

 

[journeyjim]

Have you checked the temperature sending unit? It shouldn't be running hot and the gauge showing 50%, just my 2 cents.

 

[JeepJeepster]

Yes, that is an idiot gauge. It will show 50% from like 180 to 235F(or something like that). Tjkj posted a page from the service manual that showed what temps it actually changed at. It wont change till youre already over heating. Ive got a scan gauge and can see the actual temp of the engine. Seen it up to 220 in the summer before the engine fan kicked on and it was still right in the middle.

Trying to keep the engine cooler wont really help anything. Probably run more inefficient and use more gas. Works the cooling system harder too. The cooling fan wont kick on till well over 200 anyway.

 

[tjkj2002]

Well the 180 degree hi flow stat is in and hasnt thrown the 1281 too cold OBD code yet . Whats funny is the dash gage is in the exact same position with the 180 hi flow stat in vs the factory 195 degree stat. So there must not be much resolution in that factory gage as others have stated. I have an infrared gun at work I will bring home and shoot some engine temps just for the heck of it. But it looks like this stat is a workable alternative to the 195 stat. that wont turn on the check engine light and throw a code. If it throws a code I will be sure to update this thread so nobody wastes any money. J

You will just get worse mpg's since the engine will not reach "operating temps".To many short trips when it's colder outside will pop that code again,then again you may never get the code since you will never reach the correct operating temp so a "drive cycle" will never occur.Without a completed drive cycle,takes certain conditions to be considered a drive cycle, many of the important sensors and PCM function will never be tested so you will not know of other issues that may arise.You will get the OBDII code P1000,it will not trip the MIL,which is "imcomplete drive cycle".