Cooling Help

[‘89Jimmy]

Howdy gents! I'm workin on an 89 Jimmy with a 350 Vortec. Recently replaced the thermostat, water pump, and radiator hoses, because I had no idea how old they were, but probably 10 years or so. Since then, every cold start gets up to normal operating temp, then gets up 210 or 215 before then dropping back to 195 (thermostat setting). It then settles at the 195 for as long as the truck is hot, but that initial spike has me concerned as it never happened before. I thought driving it would move any bubbles up and out the radiator cap, but it's been a few months with no change. Last night, I opened the radiator cap and watch things as it warmed up. It pushed out coolant, and continued to slowly surge every few seconds. Very rhythmic. Any ideas? Sticky thermostat opening and closing erratically maybe?

 

[Wes Harden]

Yeah stickey t stat. Most new t stats are so cheap and unreliable.

Try another one. Avoid fail safe style t stats. They fail open, usually on the first heat up

 

[‘89Jimmy]

Thanks for the input, and confirming I'm not totally crazy!

I had the Duralast Gold #15359 from Autozone, is there another you'd recommend instead?

 

[gweber71]

I have used Stant Superstat thermostats for years in both my 87 K10 and 71 Chevelle. They work great.

 

[imiceman44]

Yeah stickey t stat. Most new t stats are so cheap and unreliable.

Try another one. Avoid fail safe style t stats. They fail open, usually on the first heat up

I would rather have one be stuck open than stuck closed like the last one I had

 

[Wes Harden]

for sure it's just cost 2x as much and don't perform, They used to work fairly well. Everyone tried by people around me in the last few years has failed open on first heat cycle.

I would recommend Mr Gasket high floe tstat but i don't think they come in 195, they might.

 

[fourwheelerjeff]

for sure it's just cost 2x as much and don't perform, They used to work fairly well. Everyone tried by people around me in the last few years has failed open on first heat cycle.

I would recommend Mr Gasket high floe tstat but i don't think they come in 195, they might.

part #4365

 

[tarussell]

Thanks for the input, and confirming I'm not totally crazy!

I had the Duralast Gold #15359 from Autozone, is there another you'd recommend instead?

Autozone’s Duralast line is nothing more than a reboxing name brand gimmick - they purchase in bulk from just about any manufacturer who accepts their low bids.
Sometimes ya’ get lucky with a quality name branded part but most of the time not so much…
Buyer be ware !

I worked for them part-time while in school and was so disappointed when I learned how things worked.

 

[nvrenuf]

I need to buy a thermostat for my Blazer and from what I’ve read Robert Shaw is a really good brand and American made.

 

[‘89Jimmy]

Autozone’s Duralast line is nothing more than a reboxing name brand gimmick - they purchase in bulk from just about any manufacturer who accepts their low bids.
Sometimes ya’ get lucky with a quality name branded part but most of the time not so much…
Buyer be ware !

I worked for them part-time while in school and was so disappointed when I learned how things worked.

Hahaha, can confirm

 

[Wes Harden]

yeap autozone fan clutches are US Midwest, some of the water pumps are AC Delco. The stp oil filters are premium guard mfg, which recently purchased Fram's assets from First brands fiasco.
Raybestos has been purchased by Friction 1, and says they will be manufacturing Raybestos sometime this quarter. Autozone brakes are either Raybestos or Central Brake, both of which were owned by First brands.

A crap ton of Duralast is Dorman.

 

[nvrenuf]

Good stuff @Wes Harden