I picked up a decent looking 250 in liner for a project my dad is into. We took it apart today to clean it up and put new gaskets in it. This is where we found a small, gunky problem. The weather jackets are rather plugged up with sludge. Its loose, for the most part, just looks like it would cause a real over heating problem, not to mention plugging up the heater core and damaging the new water pump.
So my question is, what is your home remedies for this problem????
I had a Tahoe last year from Florida. And since heat was never used and it was low mileage. i wasn't shocked that i got no heat or there was rad plug crap in it.
A friend suggested run a bottle of CLR through it, let it sit for an hour. He suggested it may take 3-4 tries.
i did it and ran water till it was clear. Got heat for a week. Then plugged up again. i understand most of it was in the core but if a water jacket was restricting the flow as my engine guy explained to me it could cause it to restrict it.
So a 2nd run of it. and voila. perfect heat from there on it. i have suggested this to others having cooling issues and it has seem to resolve there temp issues.
I have seen weirder things fix things. Even apart I would let it sit and run it clean with water.
If it is that sludgy and the you have the motor out of the car, remove all the core plugs and the water pump and pressure wash it to get the big chunks out. If you can, do it on an engine stand so you can rotate the motor. Keep washing until the water coming out of all the holes is clean.
Then I use heavy Duty Foaming oven cleaner in the water jackets for a day or two. You want the old school stuff based on Caustic Soda, Sodium Hydroxide, or Lye, and then pressure wash it again. The foaming stuff sticks pretty good. If the water jackets are not clean, repeat. Sodium Hydroxide will take the rust off pretty quickly, but it will also remove the rust inhibitors from the antifreeze, so make sure your first fill is with a strong antifreeze mix. It will also remove paint, so do this before painting the block.
If anyone has put stop leak into that motor, the vinegar and CLR won't touch it since its organic based. It just makes more gunk.
Then install new core plugs. They are very cheap and they tend to rust out from the inside anyways. Its cheap insurance to replace them while the motor is out.
EDIT - don't ever mix oven cleaner with with vinegar or CLR. They react to each other pretty badly...
-- Edited by RacerRick on Friday 17th of July 2015 04:01:50 PM
Interesting. Is the ****tail that comes out an environmental concern? There is a large floor drain in the shop, but the parking lot is black top, so I wouldn't want to do this outside.
Oh yeah - I don't use oven cleaner on aluminum anything. It will strip the anodizing and eat the aluminum. And read the ingredients on the oven cleaner! Some of the new ones don't have the active ingredients you want. Look for one that has either Lye, Sodium Hydroxide, or Caustic Soda.
Wear eye protection when using the pressure washer, especially after putting the oven cleaner into the water jackets. If you get some of this stuff into your eyes - its real bad news! The pressure washer will make it go everywhere. Wear clothes you do not care about.
Remember that the active ingredients in the oven cleaner we are talking about is the same stuff used in the hot tank in your local machine shop.
Core/frost plugs out then blast that thing clean. You will be surprised how much crud/dirty water comes out. I have also poked around with various tools/rods etc to help knock out the stubborn stuff.
