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-   -   Cracked radiator and knocking (http://www.wranglerforum.com/f210/cracked-radiator-and-knocking-249677.html)

ryanhewitt 06-16-2013 09:08 AM

Cracked radiator and knocking
 
I read previous posts, and it seems the concensus is the the TJ radiator doesn't last beyond 5 yrs / 100k - as an average.

I'll try and keep my experience as short as possible. I was driving up a sandy wash in 2 high with the AC blowing, 2nd gear, ~ 15-20 mph, and about 1800-2000 rpm. Friends jeep outside thermometer said ~ 95F. I was in this combination for about 1/2 hour and the jeep was running where it always does - ~210. I got to an area that required 4 low and stated climbing a steep area in 1st gear, AC blowing, ~ 5 mph, and 2000 rpm. After about 10 seconds I noticed the temp at 230 (just starting to hit the red), I stopped the jeep, put it in neutral and set the parking brake. The temp pegged and the engine started knocking / rattling. I turned it off.

Looking under the hood there was liquid on the AC line that was oily. Radiator was relatively cool (could keep my hand on it) both hoses were warm and "squeezable". I thought the thermostate stuck so tapped on it, waited a few minutes and tried starting. It didn't want to start (like not getting fuel) but finally started and no knocking at ~ 190F.

One thing I forgot to mention was that we were off pavement, and ~ 20 miles from the nearest paved road. I really didn't want to pay for an off pavement "recovery", and the road was pretty hilly and windy - thus making a tow from my friends jeep difficult with a mine not running (no ps and no pb).

So I drove it trying to keep the RPM's low and vehicle speed high for max airflow. I got about 1 mile and the temp went to 230 again so I pulled over. This time we went to remove the radiator cap - BEING EXTREMELY CAREFUL considering the temp, and the cap came off with no pressure behind it at all. Thants when we noticed the top of the radiator was cracked. So we started adding water to the radiator (overflow was at the full mark/just under), and it took a lot. I'm thinking maybe 1.5 to 2 gal.My friend said he didn't see any coolant on the road, and the underside of the vehicle was dry.

I was able to drive the rest of the way to pavement in 2 high, 2-3rd gear, 1800 RPM, at ~ 25 mph,with the heater on, and it ran at ~ 220F. After shutting the jeep off and airing the tires back up, we decided to try and limp home as from here it was maybe 30 miles of mixed 2 lane and highway driving. We had to pull over a few times to buy more water and add as the water in the system was just turning to steam. The jeep was running on the highway ok at 65 mph and ~ 220F, but when I came to an area that required throttle input the jeep would start making the knocking / rattling that I heard when this whole thing started. I limped to a parking lot off the highway and left it there over night.

Again, sorry for the length, but I want to make sure all the information is include to the best of my recollection.

So, my questions: 1. how could this happen and no coolent be seen on the ground? The jeep had a coolant flush at the dealer last summer, and there maybe < 500 miles on it since and no offroading. Did they not fill the system to capacity or not use the correct mixture of water to coolant?

2. Is the knocking / rattling an indicator of permanent damage?

I'm going to limp the jeep over to a friend's place this morning about 1/2 mile away. I'll pull the dipstick and make sure the oil isn't contaminated/milky.

Thank you in advance.

ryanhewitt 06-17-2013 07:59 AM

Update
 
I went and picked the jeep up from the parking lot. The oil was good and it took ~ 2 gal of water in the radiator. I drove it to my friends house, with the heater on, ~ 1/2 mile, 25 - 35 mph, and no rattling / knocking. The jeep seemed to be driving like it was before the whole incident. The jeep reached ~ 200F right as I got to his house. When I pulled up it was leaking from the radiator crack and the engine compartment was wet. We pulled the radiator, looking into a replacement today, and I'll post when I get it all back together.

Thanks

tbensor 06-17-2013 10:20 AM

that is good news. The knocking could have been from fuel detonation from the heat in the cylinders. Keep an eye on it after you change the radiator. Hope the head gasket and head is still good.

ryanhewitt 06-17-2013 08:15 PM

Thanks!
 
Thanks tbensor. I was wondering if I was going to get any replies at all. Between my last post and when I read yours,I was wondering if predetonation could be occuring as well. I run the low grade fuel and it was very warm, both the motor and the ambient temperature. Like I stated in the orig post, it didn't want to start, like it wasn't getting fuel - made me think whatever is in the fuel log was cooked.

I hope the head and gasket are good as well. Like I said no water in the oil and no white smoke out the exhaust. I know that doesn't mean I'm in the clear but my fingers are crossed.

Thank you again for the reply.

tbensor 06-17-2013 08:17 PM

Quote:

Originally Posted by ryanhewitt (Post 3870981)
Thanks tbensor. I was wondering if I was going to get any replies at all. Between my last post and when I read yours,I was wondering if predetonation could be occuring as well. I run the low grade fuel and it was very warm, both the motor and the ambient temperature. Like I stated in the orig post, it didn't want to start, like it wasn't getting fuel - made me think whatever is in the fuel log was cooked.

I hope the head and gasket are good as well. Like I said no water in the oil and no white smoke out the exhaust. I know that doesn't mean I'm in the clear but my fingers are crossed.

Thank you again for the reply.

My fingers are crossed to

ryanhewitt 06-20-2013 08:35 PM

Good news!
 
Well I installed the new radiator and hoses last night and zero issues. I drove the jeep home from my friends house about 20 miles away via highway and 2 lane roads at the speed limit. Nothing. It's almost like nothing happened. I feel very fortunate to have dodged a bullet on this one. I do have a few questions though:

1-I followed the instructions in the FSM and after bringing it up to operating temp, turning it off, allowing it to cool, and the level in the overflow didn't change. Initially I added 1 gal of anti-freeze and ~ 1/2 gal of water. Seems like it should've taken some from the overflow? The level didn't change overnight either.

2-how do I know if I have all the air out of the system. Like I said I followed what the FSM said.

Thanks again!


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