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changing thermostat, upper hoses

J

jbeintherockies

NAXJA Forum User
Location
Aurora, Colorado
Hello,

Tomorrow I plan on changing the thermostat, upper radiator hose and heater hoses. I have added the coolant filter that dieselenthusiast documented on this web site and now I just need to hook up the hoses. I plan on draining some of the coolant out of the radiator in hopes to create less of a mess. When I put the fluid back in, I was planning on removing the radiator cap and adding it in there.

My question: do I need to "burp" the system and if so, how should I do it? My plan was to loosen the temp sensor that goes into the thermostat housing to let some air out. Maybe there is a better way to do this? I'm just worried I'm going to blow a head gasket or something serious like that.

Thank you in advance :NAXJA:!

2000 XJ Limited
All stock
155K miles
 
You probably don't want to drain the radiator. The drain hole in the bottom of the radiator is very fragile. Just unhook the upper hose and have a catch can under it. You are okay to refill the system through the radiator cap. In regards to burping the system, the thermostat you purchase should have a hole in the top which lets the system self purge the air.
 
Regarding thermostats, I have read good and bad about the Stant super stat and good and bad about the NAPA thermostats and all good about the Mopar thermostats.

Since I am doing the job tomorrow, would a Stant super stat or a NAPA premium 195 degree thermostat do an accurate job?
 
The last time I did all of this, I first put the drain pan underneath the lower radiator hose, loosened and drained from that. When I removed the upper hoses and such, the mess didn't happen.

All of the Stant units I've ever used worked fine. I went with the Mopar thermostat last time anyway, and it only cost me $8.00 as I remember. It has worked fine over the past 5 years.

I've never 'burped' a cooling system. The cooling system is designed to burp itself, so long as components are serviceable and no leaks are present. Do consider new coolant and distilled water as a part of your service, as well as a new radiator cap.

Have fun!
 
There is no burping procedure like on some vehicles. Fill through the radiator with the hoses on the thermostat housing off until the end. The jiggle pin in the thermostat does the rest. I use only Mopar thermostats. I use Napa radiator caps. Don't buy a failsafe.
 
Just to let you know, the new Mopar thermostats are made by Motorad, and not from the same supplier as before. When I changed mine, I got the Mopar, and my Jeep wouldn't get above 185* in winter. I swapped it with a Stant Superstat 195* and now I run a constant 200-205*. I never had a problem with Mopar stats in the past until this one, but it was also made by a different supplier. Not saying they are all bad, but I got a bad one, so just be aware.
 
If it was bad I would take it back to the dealer and put it on the counter and say give me another one.
 
Completed the job last Sunday. I only did the upper radiator hose, the heater hoses, the NAPA/WIX coolant filter (installed on the 3/4" heater feed line, not the 5/8" return line), new thermostat housing and thermostat.

I went with the Stant super stat (non-failsafe version). I drilled a 1/8" hole into the thermostat flange and placed the hole at the top when I installed it.

Two observations:
1. It takes longer for the engine to warm up,
2. which makes it take longer for the heat to warm up.

It takes a long time to get to 210, but it gets there eventually. It appears to hover around what is probably 195 much longer than before. The thermostat that was in there before was some generic 195 degree cheapo thermostat that did not have a vent hole for air to escape; I did not install that thermostat. The Stant super stat definitely looks better made (thicker flange, etc).

I also bought a Mopar thermostat; but haven't put it in yet. The Mopar thermostat has the little jiggly-thing on it, which the Stant super stat did not have.

I'm curious if the car will warm up any faster with the Mopar thermostat.

I plan on insulating the 3/4" heater feed line hose today, in hopes of keeping the heat in the now longer heater feed line.
 
Does this type of coolant filter work better than radiator hose in-line filters?

How often do you need to change the Napa/Wix coolant filter?
 
jbeintherockies said:
Completed the job last Sunday. I only did the upper radiator hose, the heater hoses, the NAPA/WIX coolant filter (installed on the 3/4" heater feed line, not the 5/8" return line), new thermostat housing and thermostat.

I went with the Stant super stat (non-failsafe version). I drilled a 1/8" hole into the thermostat flange and placed the hole at the top when I installed it.

Two observations:
1. It takes longer for the engine to warm up,
2. which makes it take longer for the heat to warm up.

It takes a long time to get to 210, but it gets there eventually. It appears to hover around what is probably 195 much longer than before. The thermostat that was in there before was some generic 195 degree cheapo thermostat that did not have a vent hole for air to escape; I did not install that thermostat. The Stant super stat definitely looks better made (thicker flange, etc).

I also bought a Mopar thermostat; but haven't put it in yet. The Mopar thermostat has the little jiggly-thing on it, which the Stant super stat did not have.

I'm curious if the car will warm up any faster with the Mopar thermostat.

I plan on insulating the 3/4" heater feed line hose today, in hopes of keeping the heat in the now longer heater feed line.
Click to expand...


The Stant Super-stats have V-notches in them that allow for a bit of coolant to flow through while the thermostat is closed. This eliminates the need to drill a hole in the top. My guess is that the hole you drilled allows for more coolant flow, which causes the engine to warm up slower.

I have the Stant Super-stat 195* and I get heat by the time I'm at the end of my road.
 
jeepkid03 said:
The Stant Super-stats have V-notches in them that allow for a bit of coolant to flow through while the thermostat is closed. This eliminates the need to drill a hole in the top. My guess is that the hole you drilled allows for more coolant flow, which causes the engine to warm up slower.

I have the Stant Super-stat 195* and I get heat by the time I'm at the end of my road.
Click to expand...

Boy do I feel stupid.

I put the Mopar thermostat in today. I found it interesting that it had 'MotoRad' stamped onto the brass portion of the stat. I naively thought mother Mopar made the thermostat just for my Jeep. Anyway, the Jeep warms up very quickly now and runs right at 210, like it always has. I will put a spot weld on the Stant thermostat where I drilled the hole and give it to my bro. He has a '96 XJ.

I also added the Prestone 2 in 1 coolant flush and cleaner today. I plan on flushing the system this Friday. When I called and talked to Prestone tech support, they said I could leave it in there for five days. But, after that, it is no longer doing anything and that is a good time to get it out of there.
 
jbeintherockies said:
Read this:
http://www.naxja.org/forum/showthread.php?t=1085589
Click to expand...

Thanks for the link.

Donaldson filters recommends changing once a year, every 140,000 miles or 4,000 hours.
I suppose the filter media must deteriorate after a while and require a one year filter change interval possibly longer when installed in a Jeep?

From what I gather from reading, an inline radiator hose filter would be less efficient than a bypass type coolant filter.

I think additional filtering is a good idea. I use an inline Megafine transmission filter (w/ built-in bypass valve) that I installed after a passive transmission flush. It's a good idea to at least install a temporary filter after a flush to catch any debris floating in the oil.

I also have an uninstalled Amsoil by-pass filter. I would need to first remove the AC unit to make room for.

One thing I don't like about the oil bypass filters is you need to have the oil tested at regular intervals. As mileage increases oil quality mainly relies on oil tests rather than a simple oil change.

Amsoil has test vehicles that have gotten over 50,000+ miles between oil changes.

By pass type filters have been around a long time. Older vehicles I've worked on some had an OE oil filter canister with a toilet paper roll or similar type media. To change the oil filter you unscrewed the top pulled out the old filter and replaced with a new one.
 
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I have a newer HD radiator, water pump with a recent flush, coolant change and have been thinking of installing a coolant filter.

So went ahead and ordered the Wix base and filter. ... cost was about ~$51.00 including shipping.

To purge the cooling system, what I do is park on an incline with a cold engine and allow it to warm up with the radiator cap removed. I also have a valve on the upper heater hose I can open to release any trapped air.

I don't completely fill up the entire cooling system until all the trapped air is gone. This also allows to make any changes to the antifreeze and distilled water ratio. I sometimes go a few days before topping the coolant off.
 
Last edited:
Muddzz said:
Thanks for the link.

Donaldson filters recommends changing once a year, every 140,000 miles or 4,000 hours.
I suppose the filter media must deteriorate after a while and require a one year filter change interval possibly longer when installed in a Jeep?

From what I gather from reading, an inline radiator hose filter would be less efficient than a bypass type coolant filter.

I think additional filtering is a good idea. I use an inline Megafine transmission filter (w/ built-in bypass valve) that I installed after a passive transmission flush. It's a good idea to at least install a temporary filter after a flush to catch any debris floating in the oil.

I also have an uninstalled Amsoil by-pass filter. I would need to first remove the AC unit to make room for.

One thing I don't like about the oil bypass filters is you need to have the oil tested at regular intervals. As mileage increases oil quality mainly relies on oil tests rather than a simple oil change.

Amsoil has test vehicles that have gotten over 50,000+ miles between oil changes.

By pass type filters have been around a long time. Older vehicles I've worked on some had an OE oil filter canister with a toilet paper roll or similar type media. To change the oil filter you unscrewed the top pulled out the old filter and replaced with a new one.
Click to expand...

Yeah, I have a Magnefine inline filter on my power steering unit's return line and on the transmission cooling return line. I do not have a cooler on the PS unit or an additional cooler on the transmission (in addition to the radiator). I was told you only need an additional trans cooler if you tow, and I do not. I may add one anyway; they aren't that expensive.
 
jbeintherockies said:
Yeah, I have a Magnefine inline filter on my power steering unit's return line and on the transmission cooling return line. I do not have a cooler on the PS unit or an additional cooler on the transmission (in addition to the radiator). I was told you only need an additional trans cooler if you tow, and I do not. I may add one anyway; they aren't that expensive.
Click to expand...

I installed a B&M cooler, with a small footprint ~7 x ~12 inches. Lowers average engine temperatures by about one or two degrees.

The AW4 has a tendency to run hot. Working temperatures should be in the ~150s to ~180s. However if you stress out the transmission it will easily rise above 200 - 225. The OE cooling system is designed primarily for on road, non towing conditions and is susceptible to running hot.

(I've read various working temperature ranges for the AW4, some have shown from a factory manual e.g. 125-176 deg. others are to ~185 deg. F)
______

I was wondering you said you warm up at 210 deg. F.. I understand some people run at hotter temps, but a 210 warm-up doesn't leave much lee-way.

After installing a HD copper/brass radiator. My warm-ups are 195 deg. F. with average running temperatures between 195 - 205. If running in heavy sand engine (CTS) temperatures will sometimes go above 210 if I don't use the aux. fan, wired to a manual over-ride switch.
 
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