Grand Cherokee coolant
#2781254
06/03/20 10:59 PM
06/03/20 10:59 PM
|
Joined: Jan 2003
Posts: 5,394 Pikes Peak Country
TC@HP2
OP
master
|
OP
master
Joined: Jan 2003
Posts: 5,394
Pikes Peak Country
|
Over the winter I picked up a reasonably clean Grand that wouldn't run. Seller said he was just driving down the street and it died. Sure, whatever, got it for a great deal.
After getting it home and checking the oil and finding 5 quarts of antifreeze sitting under the 5 quarts of oil (no it wasn't all whipped into milkshake) figured they fragged the engine. Pulled the plugs to do a compression check and found one plug sheared off and piston jammed into the head. Bingo!
Picked up a running used motor from a local salvage yard a few weeks ago. Got it in, fired it up started checking things. Everything looked good. Until the temp started creeping up. The overflow started bubbling, temp was still climbing, so I shut it down.
Next day drained the coolant out. The new coolant came out a muddy greyish-brown. Emptied it all out, disconnected the hoses, pulled out the garden hose, put the pressure trigger on it and started flushing the radiator. Started seeing a lot of metallic flakes coming out. Eventually a big blob of mud looking stuff plopped out. Kept the water flowing until it was clean. Looked out the blob of mud and it was shimmering metallic. I'm guessing the previous owner was trying to seal up a perceived head gasket leak or something.
So pushed a lot of water through the radiator. Hooked everything back up, reloaded the radiator with coolant, restarted and began watching. Everything proceeded normal, temp was climbing to normal range, around 210 the electric fan kicked on, temp slowly came down, fan turned off. This cycle repeated several times. Temp seemed stabilized and wasn't climbing over around 220, but after some time, bubbles in the overflow began again, so I shut t down. Figured I'd pick up some radiator cleaner and try another flush.
All that work was on Sunday. Tonight, Wednesday, I decided to drain the radiator. When I began to turn the cap, it was under pressure. A lot of pressure. Like 18# worth of pressure and it started blowing antifreeze out from under the cap..and it was cold antifreeze. So I turned the petcock to drain things. It only took a few turns to get flow started. Had to modulate how far I turned the petcock to keep a steady flow instead of a shooting stream.
So now I'm wondering of a cycle of cleaner and water will work at all. I have never encountered a cooling system that held that much pressure over several days . But it also has me wondering if I might have a cap issue or a bigger problem inside the radiator.
Thoughts?
|
|
|
Re: Grand Cherokee coolant
[Re: TC@HP2]
#2793542
07/06/20 05:33 PM
07/06/20 05:33 PM
|
Joined: Jan 2003
Posts: 5,394 Pikes Peak Country
TC@HP2
OP
master
|
OP
master
Joined: Jan 2003
Posts: 5,394
Pikes Peak Country
|
Update;
Did all teh work outlined above. Filled, ran, and then drained the system about six times before it stopped coming out rust colored with sparkles in it. Replaced the thermostat, replaced radiator cap, refilled system with 50/50 and idled up to 200*. Aux fan came on, everything remained around 200. There was still a fair amount of pressure in the system, temps were consistent with previous checks. After shutting off, still got bubbles in the overflow. I've been limiting use to short trips within a few blocks of home. Everything above has been repeating. Took it to work today, which is a bit further than the few blocks, and temp climbed up to about 220. Turned on defroster to keep it in check, which allowed me to complete the drive.
So it seems I haven't actually fixed anything. It still gets overly hot on occasion and still blows bubbles back into the overflow after shut down. What's next?
|
|
|
Re: Grand Cherokee coolant
[Re: TC@HP2]
#2812232
08/23/20 12:39 PM
08/23/20 12:39 PM
|
Joined: Jan 2003
Posts: 5,394 Pikes Peak Country
TC@HP2
OP
master
|
OP
master
Joined: Jan 2003
Posts: 5,394
Pikes Peak Country
|
Update:
Called the yard I purchased the engine from and explained the situation to them. They said they would provide a replacement if I'd bring in the head. So I began a careful disassembly of the top end. While removing the head bolts, I noticed four front most head bolts did not require as much effort to remove and the left front one came out with most the threads on it stripped and deformed. Examining the head gasket, I could see what appeared to be coolant stains between #1 cylinder and the front most water jackets. Also noticed it had a Victor-Heinz gasket. Not sure, but I don't think these are OEM. A visual inspection of the had did not reveal any obvious cracks. These typically crack between the 3-4 cylinder valve springs or on the deck.
Took the head into a shop for magna-flux inspection. They called and said good news was they could not find any cracks. Bad news was the head was warped .012. I asked if they could cut it to level it out and they said they could. Just got it back this week. I also chased all the head bolt holes in the block with special attention those front four. They all tapped out smoothly and without what appears to be any issue.
Also pulled an oil sample and sent that in for an analysis. Curious about metal content to see if bearings got cooked as a side effect of this. Unlike most 4.0 cracked issues with the engine consuming coolant, my coolant levels never dropped. I simply had extremely high pressure in the system and bubbles. My hope is the engine was not ingesting coolant and diluting the oil, thus saving the bearings, but the analysis will tell me that.
So I'm in $30 for the inspection and $60 the milling, $60 for a new top end gasket kit with new head bolts and valve guide seals, another $20 for the oil analysis. So not too expensive yet.
|
|
|
|
|