New thermostat does not fit, please help!

**v8unleashed** · 04-12-2008, 03:39 PM

I picked up a thermostat at pepboys yesterday, and after I take the old one out today I find out the new one doesn't fit. I called pepboys, and they confirmed I have the right part number.

The new one looks just like the one that SLP lists, but the lips on the housing that stick out and hold the actual thermostat to the housing are too wide to fit into the hole in my block.

Any ideas? Thanks.

**9t8z28** · 04-12-2008, 08:33 PM

You got the wrong one.

**Mr. Luos** · 04-12-2008, 08:41 PM

Picture doesn't work.
But I would also assume you somehow got the wrong one.

Take it back, and go to a good parts store.

**STL2SLO** · 04-13-2008, 05:36 AM

I know on the trucks at least there were 2 different water pump manufactures so the tstats from 1 won't work on the other.

**mrr23** · 04-13-2008, 06:44 AM

there was a water pump design change in 2004. if your water pump was ever changed out, you may have the newer design (2004-up). without seeing the pic of what you got and what you have, we can't tell.

**sunsetorangess** · 04-13-2008, 07:46 AM

Whats the part number on the thermo you have? and brand.
J

**v8unleashed** · 04-14-2008, 06:04 AM

Originally Posted by mrr23

there was a water pump design change in 2004. if your water pump was ever changed out, you may have the newer design (2004-up). without seeing the pic of what you got and what you have, we can't tell.

Thank you. This appears to be what happened. I went to the dealership this morning. I told him what you said about the design change. First he pulled out the same wrong one. Then after 10 minutes of looking, he "discovered" that they had a design change in 2004. Clever guy. Except they didn't have it in stock.

I asked if an auto parts store would have it...he said no. I'm sure he's full of crap, but I ordered it to get it tomorrow anyway.

Do you know an example of a car they would have used the thermostat on, so if I try a parts store today, I can give them a make/model/engine to look at that thermostat?

Thank you!

**2001NBMZ28** · 04-14-2008, 06:29 AM

Sounds like you have the new design pump. Go to thunderracing.com and do a product search for 28-100228, has a pic of the stat for the 04-05 LS1/2 GTO/Corvette/Trucks and see if it looks like yours.

Edit: Post looks like there's a space after the dash, but shouldn't be there.

**v8unleashed** · 04-14-2008, 06:51 AM

Originally Posted by 2001NBMZ28

Sounds like you have the new design pump. Go to thunderracing.com and do a product search for 28-100228, has a pic of the stat for the 04-05 LS1/2 GTO/Corvette/Trucks and see if it looks like yours.

Edit: Post looks like there's a space after the dash, but shouldn't be there.

Yeah, that's the one...so I'll ask for an '04 vette thermostat, I guess. Thank you.

It's never as easy as you think it will be, is it?

**bostonz28** · 04-17-2008, 03:40 PM

I bought the 160* Tstat off Jegs a week ago and It was that GTO/Truck one

WTF! it was cheap ne ways so I went to the chevy dealership and they wanted $80 bucks for the stock one lol what a joke I went to AutoZone and got a 180* ACdelco one for like 20 bucks and it runs awsome now they had the 160* tstat also

**Firebirdjones** · 04-17-2008, 05:02 PM

I went through this recently. All the aftermarket stats I came accross were for the newer design (LS2) and would not fit inside the LS1 thermostat housing. I haven't found any autoparts stores around here that even carried the LS1 stat,,,,a colder one at least. They all want to sell me the larger LS2 stat,,,,and their applications all say LS1,,,,,ugh.

Beware they even list them in the summit and jegs catalogs this way,,,,,but when they come in you'll find it's also the larger LS2 stat,,,,ugh again.