Compression test results Questions

[CameronB]

I hope all of that baking soda came out. A few years ago, I read that you should put "comet" powder in with your flush, and that it would clean out the block real well. Well, I still find traces of comet in there when I work on it. It would find the low points of the cooling system and settle out into a fairly hard sludge. Maybe baking soda will stay in solution better.

 

[xjmatt]

I hope all of that baking soda came out. A few years ago, I read that you should put "comet" powder in with your flush, and that it would clean out the block real well. Well, I still find traces of comet in there when I work on it. It would find the low points of the cooling system and settle out into a fairly hard sludge. Maybe baking soda will stay in solution better.

I was worried about exactly that myself. I put a fair amount of effort into dissolving the baking soda in solution. I mixed the 2 gallons of distilled water in a bucket with the baking soda the night before I put it in and mixed and mixed and mixed. Next day I drained the vinegar and setup a siphon to get the baking soda solution into the radiator. When the siphon was done there was a 1/2" of water left in the bottom of the bucket and a baking soda film on the bottom. Figure that was just was not going to dissolve into the solution no matter what.

Also the day I drained the baking soda mix I did start the motor and let it run about 20-30 seconds or so. I don't know if that did any good at all but might have helped kick up any that my have settled in the low spots and wasn't enough to pressurize the system.

 

[xjmatt]

My 94 is having the same problems, except mine does fine unless I'm driving in the city traffic or going under about 30 mph. Replaced the fan clutch, the t-stat, t-stat housing, water pump, radiator is a 3-core about a year old, upper and lower hoses. She runs fine if I drive with the heat on, but that sucks. I don't know the temp, since I only have a dummy light. I may try the vinegar/water baking soda/water technique and see how that goes.

If you've replaced all that and it still overheats in city traffic I'd check your electric fan. Since you don't have a temp gauge see if you can find yourself/borrow an IR gun and see if the fan kicks on at 220°F when it's supposed to. If not check/replace the relay and maybe the temp sensors too.