engine temp switch

[74chev4x4]

nope drove it alot with no tstat and she was fine, just put a new temp gauge on it and it says at idle its running about 200-205 degrees?

[Irish_Alley]

is that with or without the stat

[beastie_3]

you got a cheap temp gauge?

[74chev4x4]

With the tstat, that's what its running.  Yea new guage

[Irish_Alley]

whats it running at at highway speeds?
200 is a little high but it could be worse my truck is at about 170 idle and goes to 180 driving

[beastie_3]

Did the gauge come with a new sending unit? What was the condition of the engine when you put it in, rebuilt?

[74chev4x4]

Motor was rebuilt 15 k ago I was told, I only had enough time to piut the gauge in last night no time to drive it. I was thinking maybe I should put in a 160 tstat?

[74chev4x4]

yea the gauge came with a new sending unit, I was thinking if I put the 160 degree tstat in it would probably run the truck about 180 or so, that would be better, any thoughts on that?

[74chev4x4]

ok drove it this morning, if you are barely on the gas it will stay about 200 get on the gas what so ever and the gauge climbs like a speedo, this is the new gauge by the way.  On a flat I got on it some and the gauge almost hit 240 degrees.  I feel like just going out and spending 2k and getting a crate motor and new radiator and throwing taking this pos up for scrap metal.

[beastie_3]

It sounds like your radiator is working fine if it worked fine before the swap. Since it is a used engine, there is no telling.

Is it a 350? Get the casting number on the ridge above the oil filter. You have to look down behind the valve cover. I wonder if you got ripped off and it is a 400, which has a history of cooling issues. Just a thought.

Have you checked the oil to see if there is water/coolant mixed in?

[beastie_3]

I wonder if someone used the wrong head gaskets...

[Irish_Alley]

see im thinking the other way since it runs fine with out the stat in and with it in it hold the water back more causing more restriction and with a restricted rad it would cause it to over heat water in the oil wouldn’t cause it to over heat since if it was coming out the exhaust then yes it would over heat and since hes not losing antifreeze I don’t see that being likely. Also blow head gasket would bubble out once he took the cap off

[74chev4x4]

Nope its a 350, I was kinda mad after I bought it cause I found out it has the stupid 305 heads on it, but its a 350 2bolt main.  Didn't see any oil in the coolant or any coolant in the oil or any foam under the breathers on the valve covers.  So you guys think its the radiator, I am so stumped on this one and I just want to drive my truck so I'm willing to throw so money at the problem.  If you guys think its the radiator then hey I will go buy a new 3 row alluminum tomorrow just wana drive my truck after all this work.  Thanks guys, for everyone else sick of seeing this thread sorry just had to do it again

[beastie_3]

I suppose it could be possible the 350 block dumped some crud into your radiator. Hate to see you dump $ for a new one. Maybe pull the radiator and flush it?

[74chev4x4]

Beastie, anything else I can check for a blown hg, I will flush it.