1987cutlass

I have a 1987 cutlass I've have for about 3 years haven't drove it in about 2 years I finally pulled it out of gramps garage and it started having overheating issues I changed the thermostat and now I can't screw the 2 bolts back in like there's not enough thread or somthing anyone have and suggestions and there is some really dark brown stuff in my radiator looks almost like dark brown mud need help asap
Thank u
Cane.

1970cs

Welcome to C.O.! What do the threads look like on the intake and the bolts? Pictures of hardware would help.

Get some radiator flush products, try flushing radiator and system with fresh water several times.

Pat

MDchanic

+1. You didn't happen to have plain water in it, did you?

See how it goes after a really good flush with the proper flushing substance and lots of water.
It would be best to remove the 3 or 4 water jacket plugs from the block, as well (located nearly behind the lower parts of the exhaust manifolds).

After all of that, you may need a radiator anyway.

- Eric

oldcutlass

Welcome to the site, I moved your post here to get additional views to your problem. The reason your bolts may not start is the threads may need to be chased with a tap. I always us a thread sealer on the bolts like plumbers pipe dope. I also recommend flushing your cooling system for starters.

olds 307 and 403

As said flush it out with block plugs out. It will need flushed multiple times. You can JB Weld studs in, if the threads are buggered.

MDchanic

Ewwwwww.

Or tap out the holes larger.

Or HeliCoil them.

- Eric

olds 307 and 403

It is a swirl port 307, no loss if it dies. If it is mixed properly, it will hold for many miles. Yes, tapping or a helicoil is another option. Willing to bet it is stripped.

1987cutlass

I got it thanks everyone I just bought a new thermostat housing and got a little bit bigger bolts and put them in she running very good now thanks for the info