Sup guys. Got done with the motor replacement in my father in laws 99 cherokee sport over the weekend. Got a motor with 101k on it. Runs like a champ. Before i installed the JY replacement, i noticed that there was alot of buildup in the block when i changed waterpumps. I cleaned it out the best i could. I flushed the system yesterday a few times with water, then ran a bottle of Peak cleaner through it and drove it around for a while. Im gonna drive it around some more this evening when i get home then flush it again. The motor sat at the yard for about a year and a half so it accumilated alot of rust in the waterways. The radiator cleans up nicely when flushed. Will the Peak cleaner knock down the rust buildup or should i try some dish soap or CLR? It is pretty nasty. Thanks in advance

 

I've found the best way to flush the motor is with the t-stat and water pump removed......stick a garden hose in the the t-stat hole and flush, flush, flush. Next best way is with the t-stat cover and water pump both on, remove the heater hose at the t-stat cover and remove the bottom rad hose at the water pump. Stick the garden hose in the heater hose nipple on the t-stat cover and flush, flush, flush. Need to keep close tabs on coolant color as it will probably turn rusty again quickly. Drain, flush and re-fill and again, keep close tabs on the color. U'll start to see drain/re-fill intervals get longer before the coolant discolors/gets rusty.

The CLR web site says "do not use in automotive cooling systems".

 

Not trying to hijack a thread. I just picked up a bottle of that prestone flush chemical. Mine is dirty as hell too. And I noticed silver particles, like stop leak.
One guy at the parts store told me not to use it, and just use the t fitting. he said the chemical would break loose undwanted things and any sealer and cause a leak?
The other guy told me I will never get it all cleaned without the chemical??

 

Yea i flushed using the methods ive seen you tell other members. And ive read some people say not to use CLR and others say they have with good results. I figure i will just have to flush, fill, drive, flush, fill, drive and so on till it comes clean. I flushed it yesterday and put in a bottle of the Peak cleaner with water and drove it around for about an hour and the temp never got over about 165. It was 50* outside tho.

 

It would be better to clean it out and fix a possible leak then try to cover up a leak.

 

with 165 temp, something's not right.....are u running without a t-sat?

 

No. I installed a new 195* in it. I didnt think it should be running that cool. Possible cause?

 

Bad gauge/sending unit, something electrical. Did u test the new t-stat?....been known to be bad even when new.

 

I use Dawn dish soap! This method works on M38A1 Jeep and tractors made in the 1930's. After several flush and fills the water jackets are very clean! With any cleaning activity, you run the chance of loosening something that will cause problems later.

 

No i didnt test it. Before i flushed, it ran right around 215. After the flush, with just the cleaner and straight water, it didnt go over 170* even idling for 10-15 min. Outside temp before the flush was about 70-75. After the flush was about 45-50 if it matters.

 

Definitely sounds like something is wrong. I cant image mine running that cool for that long. I flush/fill mine every single spring/summer and put in a new t-stat and even in the dead of winter when its -20 here (yes, NEGATIVE 20) mine will still heat up to 210 in about 15-20 minutes of driving around town.

 

What would cause this change of temp only doing a flush with water?? Doesnt make since.

 

What type of coolant do you all recomend during te flush and fill stages and after its flushed out? premix? straight coolant? any particular brands?

 

If doing a flush, fill it with straight as the remaining water will dilute it. I don't buy the 50/50 myself as you pay more for half the product. I also use conventional green coolant in everything except newer gm's or other new cars that have special blends.

 

Would there be any significant change in temps running straight water vs antifreeze?