Well…what do you think it was?
Some history…
I’ve been experiencing some engine cooling issues since November 2005. I first noticed it while pulling my tent trailer to Surf-n-Turf 2005 – before then, I never had an issue.
I really noticed a problem while pulling the same tent trailer to Moab for CM06. On the long uphill grades through the Sierra Nevadas and the various mountain ranges in Nevada and Utah, the needle on the OEM temp gauge was getting very close to red. I spent most of the time on the road with the A/C off, the heater on and blasting full; this helped, but I knew I had to do something.
Around town without the trailer and on the trail, everything seemed fine until last month. On a hot day, I had the A/C blowing and noticed the needle on the temp gauge slowing moving upward. I wanted to approach this systematically so I could figure out what specifically was the cause of the problem – old coolant? Fan clutch? Radiator?
The first attempt…
I started with the coolant. I flushed the cooling system on June 30th in preparation for a short trip to my friend’s cabin near Mt. Lassen. They were going to have a very full house with other friends and family, so I volunteered to pull my trailer there so there would be room for more in their cabin. The flush went fairly uneventfully. I had a hell of a time locating the petcock for the radiator – in fact, I never did find the damned thing, so I ended up pulling the lower radiator hose. I drained the block, replaced the radiator hose and ran about 4 gallons of distilled water through the system, draining a couple times until everything ran clear. I did find some sediment in the coolant, but nothing too abnormal. No sludge, no slime…nothing really ugly. I made sure to run the rear heater to be sure to get the old stuff out of there as well. I refilled with a 50/50 mix of Toyota red.
On the road, everything was fine for the first hour. To be safe, I took a flatter route with fewer long uphill grades. It was nice…more scenic than my normal route, but it did tack on an extra half-hour to an already long 3.5 hour drive. The needle on the temp gauge started to rise on the first hill…same as before. Damn!
We made it there, but it was a warm drive with the heater on…in July
Attempt #2…
With a trip planned to Big Sur with the wife and kids (and trailer) for the week of July 10th, so I decided to try the fan clutch next. On the Saturday before the trip, I started working on the fan clutch. Once I removed the 4 bolts that hold the fan/clutch assembly to the water pump, I found that I could not remove it without removing the fan shroud…yeah…I know the instructions say to do that, but I was hoping I could somehow work it through. I removed the 2 bolts that hold the shroud to the radiator and started to wiggle it free. I was being very careful to not damage the shroud since I recall them being a bit on the pricey side.
As the shroud was coming out, I somehow managed to hit the small coolant return hose – the one on the top of the radiator…and the nipple that the hose is connected to snapped off. NOOOOOOOOOOOOO!!!
I couldn’t have hit it very hard.
I looked at the small nub on the radiator for a few minutes, hoping that there might be enough of it left on the radiator to clamp the hose to. No dice. Luckily for me, I had a radiator on hand. I was planning on replacing the radiator at some point, so I ordered one from CDan. I was going to replace the old one…but not this particular weekend…not when I had a bunch of stuff to do to prep for almost a week away from home. Oh well. No choice but to dive into it. So much for the systematic approach.
I removed the battery and battery tray. I pulled the fan shroud and fan/clutch assembly. By then it was starting to get dark, so I decided to call it a day and read up on the numerous radiator replacement threads we’ve had recently. Very good write-ups guys, I appreciate the great info – since the steps have already been posted in a couple threads, I won’t repeat any of it here. But, one thing I will note is that if you’re planning on doing a complete swap of the 95-97 radiator with a 93-94 radiator, don’t bother monkeying with the bottom radiator bracket bolts – you’re going to need to remove both sides of the old bracket anyway. Remove the 4 nuts, 2 on each side of the radiator that hold the radiator to the lower mounting brackets as well as two bolts next to each headlamp – the ones for the two upper mounting brackets. I removed the grill when doing this since it gave me better access. Having the ARB bull bar on made it a little challenging to access the nuts. I had to remove my Lightforce lights to gain better access. For everything else, I followed the instructions in the other threads. Nothing significant to report. No signs of leaking out of any of the hoses – in fact, the old hoses look pretty good – I’ll be keeping these in the rig as spares…just in case.
I replaced the thermostat (and gasket) while I was at it…might as well since I’m in there already, right? Again, I went with OEM and had ordered it from CDan about week before I needed to do the work. One thing to note when replacing radiator hoses, the two lower hoses are MUCH easier to install when you have the pipe off to change the thermostat. Be sure to unbolt the short section of metal pipe between the two hoses first. If you look from underneath the engine, it’s very easy to see where they’re bolted on.
The old radiator looked good. No signs of gunk or any kind of build up. The coolant that I collected looked good…but I didn’t expect anything negative from the coolant since I’d just replaced it a week earlier. The new radiator went in with no problems. All new hoses installed, new fan clutch bolted on with no issues either. I did have some problems getting the fan shroud back in. It was a very tight squeeze on the DS side where the oil coolant hose lives – the one that’s attached to the shroud. I could not for the life of me get the tab of the shroud into the slot on the radiator. Never did get it on there completely…there’s a small gap between the shroud and the radiator. I tried for over 30 minutes, then finally threw in the towel. If I have to, I’ll stuff some high-temp spongy-type foam insulation to fill in the gap between the radiator and the shroud. With everything installed again, I refilled the radiator with a 50/50 mix of Toyota red and distilled water. I went out for a test drive…the needle stayed at it’s normal mark – just under halfway, but I wasn’t pulling the trailer either…so the real test would come the next day.
The end result…
On Monday, I got everything and everyone loaded into the rig, hooked up the trailer and hit the road. I was watching the OEM temp gauge like a hawk…nothing happened. No change at all during the 4 hour drive. I floored it when going up hills to see what would happen…nothing. Same with the return trip…not a problem. The needle never moved higher than it’s normal mark.
I realize that the OEM gauge may not be very sensitive and that I might’ve had fluctuations in temperatures while pulling the trailer up some of the grades. That said, whatever fluctuations I might’ve had was much less than what I had before swapping everything out. I’m comfortable knowing that my cooling issues have been resolved.
Some history…
I’ve been experiencing some engine cooling issues since November 2005. I first noticed it while pulling my tent trailer to Surf-n-Turf 2005 – before then, I never had an issue.
I really noticed a problem while pulling the same tent trailer to Moab for CM06. On the long uphill grades through the Sierra Nevadas and the various mountain ranges in Nevada and Utah, the needle on the OEM temp gauge was getting very close to red. I spent most of the time on the road with the A/C off, the heater on and blasting full; this helped, but I knew I had to do something.
Around town without the trailer and on the trail, everything seemed fine until last month. On a hot day, I had the A/C blowing and noticed the needle on the temp gauge slowing moving upward. I wanted to approach this systematically so I could figure out what specifically was the cause of the problem – old coolant? Fan clutch? Radiator?
The first attempt…
I started with the coolant. I flushed the cooling system on June 30th in preparation for a short trip to my friend’s cabin near Mt. Lassen. They were going to have a very full house with other friends and family, so I volunteered to pull my trailer there so there would be room for more in their cabin. The flush went fairly uneventfully. I had a hell of a time locating the petcock for the radiator – in fact, I never did find the damned thing, so I ended up pulling the lower radiator hose. I drained the block, replaced the radiator hose and ran about 4 gallons of distilled water through the system, draining a couple times until everything ran clear. I did find some sediment in the coolant, but nothing too abnormal. No sludge, no slime…nothing really ugly. I made sure to run the rear heater to be sure to get the old stuff out of there as well. I refilled with a 50/50 mix of Toyota red.
On the road, everything was fine for the first hour. To be safe, I took a flatter route with fewer long uphill grades. It was nice…more scenic than my normal route, but it did tack on an extra half-hour to an already long 3.5 hour drive. The needle on the temp gauge started to rise on the first hill…same as before. Damn!
We made it there, but it was a warm drive with the heater on…in July
Attempt #2…
With a trip planned to Big Sur with the wife and kids (and trailer) for the week of July 10th, so I decided to try the fan clutch next. On the Saturday before the trip, I started working on the fan clutch. Once I removed the 4 bolts that hold the fan/clutch assembly to the water pump, I found that I could not remove it without removing the fan shroud…yeah…I know the instructions say to do that, but I was hoping I could somehow work it through. I removed the 2 bolts that hold the shroud to the radiator and started to wiggle it free. I was being very careful to not damage the shroud since I recall them being a bit on the pricey side.
As the shroud was coming out, I somehow managed to hit the small coolant return hose – the one on the top of the radiator…and the nipple that the hose is connected to snapped off. NOOOOOOOOOOOOO!!!
I couldn’t have hit it very hard.I looked at the small nub on the radiator for a few minutes, hoping that there might be enough of it left on the radiator to clamp the hose to. No dice. Luckily for me, I had a radiator on hand. I was planning on replacing the radiator at some point, so I ordered one from CDan. I was going to replace the old one…but not this particular weekend…not when I had a bunch of stuff to do to prep for almost a week away from home. Oh well. No choice but to dive into it. So much for the systematic approach.
I removed the battery and battery tray. I pulled the fan shroud and fan/clutch assembly. By then it was starting to get dark, so I decided to call it a day and read up on the numerous radiator replacement threads we’ve had recently. Very good write-ups guys, I appreciate the great info – since the steps have already been posted in a couple threads, I won’t repeat any of it here. But, one thing I will note is that if you’re planning on doing a complete swap of the 95-97 radiator with a 93-94 radiator, don’t bother monkeying with the bottom radiator bracket bolts – you’re going to need to remove both sides of the old bracket anyway. Remove the 4 nuts, 2 on each side of the radiator that hold the radiator to the lower mounting brackets as well as two bolts next to each headlamp – the ones for the two upper mounting brackets. I removed the grill when doing this since it gave me better access. Having the ARB bull bar on made it a little challenging to access the nuts. I had to remove my Lightforce lights to gain better access. For everything else, I followed the instructions in the other threads. Nothing significant to report. No signs of leaking out of any of the hoses – in fact, the old hoses look pretty good – I’ll be keeping these in the rig as spares…just in case.
I replaced the thermostat (and gasket) while I was at it…might as well since I’m in there already, right? Again, I went with OEM and had ordered it from CDan about week before I needed to do the work. One thing to note when replacing radiator hoses, the two lower hoses are MUCH easier to install when you have the pipe off to change the thermostat. Be sure to unbolt the short section of metal pipe between the two hoses first. If you look from underneath the engine, it’s very easy to see where they’re bolted on.
The old radiator looked good. No signs of gunk or any kind of build up. The coolant that I collected looked good…but I didn’t expect anything negative from the coolant since I’d just replaced it a week earlier. The new radiator went in with no problems. All new hoses installed, new fan clutch bolted on with no issues either. I did have some problems getting the fan shroud back in. It was a very tight squeeze on the DS side where the oil coolant hose lives – the one that’s attached to the shroud. I could not for the life of me get the tab of the shroud into the slot on the radiator. Never did get it on there completely…there’s a small gap between the shroud and the radiator. I tried for over 30 minutes, then finally threw in the towel. If I have to, I’ll stuff some high-temp spongy-type foam insulation to fill in the gap between the radiator and the shroud. With everything installed again, I refilled the radiator with a 50/50 mix of Toyota red and distilled water. I went out for a test drive…the needle stayed at it’s normal mark – just under halfway, but I wasn’t pulling the trailer either…so the real test would come the next day.
The end result…
On Monday, I got everything and everyone loaded into the rig, hooked up the trailer and hit the road. I was watching the OEM temp gauge like a hawk…nothing happened. No change at all during the 4 hour drive. I floored it when going up hills to see what would happen…nothing. Same with the return trip…not a problem. The needle never moved higher than it’s normal mark.
I realize that the OEM gauge may not be very sensitive and that I might’ve had fluctuations in temperatures while pulling the trailer up some of the grades. That said, whatever fluctuations I might’ve had was much less than what I had before swapping everything out. I’m comfortable knowing that my cooling issues have been resolved.
