Cruiser Weight Low Coolant/Radiator 110,000 Miles (6 Viewers)

[Cruiser Weight]

The day after having driven for hours in 100 degree heat, I noticed the level of coolant in my overflow tank was almost non-existent. It also looks like my radiator is about due to be replaced.

I have NOT found easily visible coolant leaks, having checked above the bell housing, around the water pump, and poking around the intake manifold.

Before I go tearing into the intake, is it worth filling the overflow tank and measuring the coolant loss? I'll do the repair if need be to avoid owning a 7,000 pound paper weight, but I'm not looking to do more work than necessary.

Has anyone here used the J2hundy.com valley plate kit? What are your opinions on a gasket versus FIPG?

Thanks!

 

[Sandroad]

Unless it’s been years since you last checked the expansion tank coolant level, there is no need to do any tests, you have a leak somewhere. You’ll need to more carefully check for leaks externally and especially under the intake manifold. I suspect you’ll find the telltale pink crust there. Meanwhile, is the radiator coolant level ok?

 

[Cruiser Weight]

Unless it’s been years since you last checked the expansion tank coolant level, there is no need to do any tests, you have a leak somewhere. You’ll need to more carefully check for leaks externally and especially under the intake manifold. I suspect you’ll find the telltale pink crust there. Meanwhile, is the radiator coolant level ok?

I haven't popped the cap off of the radiator yet, but I'll check. I *think* I checked the coolant level when I bought the truck in October of 2024 and when I left for Cruise Moab last April, but I didn't know about this issue until the last couple of months, so I don't have a solid baseline. All I know for certain is the truck was happily cruising at a bit cooler than halfway on the temperature gauge in the 100 degree heat.

I think I'll:

1) Replace the spark plugs while the engine is cold (original reason I was under the hood);
2) Poke around as best I can with the air filter box out of the way;
3) Top off the coolant reservoir and check the radiator level;
4) Order the new radiator and associated valley plate parts;
5) Drive the truck and assesss until the parts arrive; and
6) Pull the intake when I do the radiator.

Thanks!

 

[linuxgod]

Could be the valley plate. Could be the water pump or a few other places that can leak. Top it off, watch it, and keep looking for the source of the leak.

 

[Cruiser Weight]

Could be the valley plate. Could be the water pump or a few other places that can leak. Top it off, watch it, and keep looking for the source of the leak.

What other locations should I watch? Thanks!

 

[linuxgod]

What other locations should I watch? Thanks!

Heater hose T’s can start to leak but your mileage is pretty low for that.

I’ve seen someone who had a leak in the rear heater line. That uncommon though.

 

[Cruiser Weight]

Yesterday, I changed the spark plugs to see if there were any signs of head gaskets going bad. The plugs are arranged with the top left cylinder eight and the bottom right cylinder one. Any thoughts?

I suspect they've been changed before since my truck was missing a fastener to some sort of breather tube on passenger side valve cover by the firewall, and a wiring harness clip on the driver's side was broken in about the place I would expect an a55hole rushing the job to do so, and a few hose clamps are... clamping nothing. At least they were factory plugs.

I filled the coolant reservoir to the "F" mark, but shot myself in the foot for diagnoses purposes since I spilled some coolant around the water pump. After hosing off the spill, I ran the truck in the driveway for about 10 minutes. I did not see any signs the water pump was leaking.

This morning, I peeked at the reservoir level, and saw it dropped a bit. I'll drive the truck today, and poke around again tomorrow.

 

[linuxgod]

If it was low you might need top it off a few times. Once it gets below L you can get some air in the system which can take a little time to burp out, so don’t freak out if it doesn’t stay at F.

 

[manofthewoods]

Yesterday, I changed the spark plugs to see if there were any signs of head gaskets going bad. The plugs are arranged with the top left cylinder eight and the bottom right cylinder one. Any thoughts?

I suspect they've been changed before since my truck was missing a fastener to some sort of breather tube on passenger side valve cover by the firewall, and a wiring harness clip on the driver's side was broken in about the place I would expect an a55hole rushing the job to do so, and a few hose clamps are... clamping nothing. At least they were factory plugs.

I filled the coolant reservoir to the "F" mark, but shot myself in the foot for diagnoses purposes since I spilled some coolant around the water pump. After hosing off the spill, I ran the truck in the driveway for about 10 minutes. I did not see any signs the water pump was leaking.

This morning, I peeked at the reservoir level, and saw it dropped a bit. I'll drive the truck today, and poke around again tomorrow.

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My semi-professional opinion...
Spark plugs look good

 

[Kernal]

There's a UV Dye (leak detector) that you can put into the radiator (cold) then after running the engine through a hot/cold cycle start looking to see if the dye shows up anywhere. FWIW

 

[Cruiser Weight]

There's a UV Dye (leak detector) that you can put into the radiator (cold) then after running the engine through a hot/cold cycle start looking to see if the dye shows up anywhere. FWIW

Thank you!

 

[GrouchyTech]

If those spark plugs were factory original they should have a “+” marked on the tip of the terminal.

 

[bloc]

You don’t need UV dye in the coolant. There are a handful of places that commonly have issues on these rigs., do your research and watch those places methodically and you’ll figure it out.

Most likely it’s the valley plate.

What year is your 200? Maybe put that in your sig. heater T material got upgraded in 2013 so they are typically only a concern in 08-11 build years.

 

[Cruiser Weight]

You don’t need UV dye in the coolant. There are a handful of places that commonly have issues on these rigs., do your research and watch those places methodically and you’ll figure it out.

Most likely it’s the valley plate.

What year is your 200? Maybe put that in your sig. heater T material got upgraded in 2013 so they are typically only a concern in 08-11 build years.

I have a 2013. Thanks!

 

[NeilC]

My guess is valley leak too. If you have a borescope, you can snake it under the intake manifold next to the PCV valve. Any sign of pink crusties at the base of the head will be confirmation. To those that dont pop their hoods and check fluid levels at least weekly, please do start now. I think most of the head gasket issues we hear about with these engines relate to situation exactly like this.

 

[CanBruiser]

In your photo, it looks like a hairline crack is starting on your rad right in front of the raised square area with the part number, same place most of them (including mine) fail I assume. Maybe something to keep an eye on while waiting for the new one.

 

[Kernal]

"You don’t need UV dye in the coolant"

Adding a UV dye into the coolant is a relatively cheap method for a do-it-yourself diagnosis, then with a UV light source watch for where the glowing coolant first appears.

Better, borrow/purchase a cooling system pressure tester, hook it up to the radiator (remove the cap, cold engine), and pump it up to the same pressure
as the system (written on the cap) then watch for the leak to appear.

Best, do both if the leak still isn't showing up with the pressure tester.

Either way, it will show up sooner or later.