Green87

Just like the title says, I had the radiator in my '87 XJ 4.0 replaced. I also replaced the coolent reservoir. The repair manual says that when you drain the radiator, you're also supposed to drain the coolent out of the block using the drain plug under the exhaust manifold. I'm not sure if the guy I had doing this drained the block. It seems to run ok. I'm just curious if it has air in the system now, and if it will overheat? The temp gauge never goes above 195-200, but it never has since I owned it.

Any ideas?

Green87

I was hoping to drive the thing to work tomorrow. Its a 45 min drive and I'm just a lil' nervous about maybe having air in the system.

What can happen if there is air in the system? Can it be driven that way?
Again, I'm not 100% sure he didn't drain the block, it's just that not too many non-XJ know about the 4.0's drain plug on the block.

Radi

I think you're OK. IMHO draining the block is to get all the old coolant out, not to get air out. At worst you might still have a bit of old coolant mixed with the new. If it is running at normal temperature I wouldn't worry too much about it.

Green87

Ok, cool.

I'm glad to have the thing back. It helps keep the miles off my G6.

tjwalker

Agree with Radi. You're fine. I change coolant on a regular basis and I never drain the block.