D2 Cooling Issues

M

MStudt

Member
Feb 6, 2017
14
0
Columbia
Yes this is my first post, and yes it's about heating issues so please be kind.

Let's start from the top so you can see what I've done. My old worn out 4.6 from my 04 had a slipped sleeve, and I didn't repair it. I ended up buying a 4.6 from Turner with SAI heads installed, and a new front cover. I installed my used water pump with about 5k miles on it. I also installed a new radiator, t-stat (180*), sensors, hoses, and over flow tank. After all this the engine fired up, and everything was great for the first 450 miles.

One the way to my inlaws, and after a 50 mile commute I notice temps at 210*. I didn't think much of it until the drive home when temps were at 227* on the highway. I did some digging around to find the fan clutch was toast, and the AC condenser fan was seized. I replaced both of those, and nothing changed. Now, I'm running out of time to get the Rover running since we're supposed to leave on 7/1 to start living from this Rover for the next couple years.

I took the Rover into a trusted shop, and they pointed to the t stat. After replacing the t-stat, and flushing the system nothing changed. They want to start putting new parts on it to see what fixes it, and I said no to that. First thing tomorrow I'm picking it up, and I'm going to start digging on it. I'm going to get an inferred heat gun reading of all the hoses to see temps there. I figure this will let me know if I have a clog in the radiator at least. Or, maybe even a clogged heater core. Next I plan on checking the new sensors I bought to see if it failed on me.

I'd also like to add that I have zero coolant leaking from the Rover. Anything else that I should be checking for?

Thanks,
Mike
 
Last edited:
M

MStudt

Member
Feb 6, 2017
14
0
Columbia
wrldky said:
First of all the work you have done is awesome! This is a basic question but the system has been bled?
Click to expand...

The system is now bled down correctly, and I have zero air in the system.

I just received an update on this, and it seems like my condenser fan is running backwards. I guess you can say that I had a blonde moment. Once that's fixed we'll know if it helped at all. With any luck that's the issue.

I also asked them a few questions about what they checked. They informed me that the radiator, and heater core were both clog free. The cooling system is air tight, and holding pressure just fine. A new 180* t-stat was installed, and the system was flushed and burped. They also added a bottle of Water Wetter to further help control the temps. They noticed at low RPM's that the temp wanted to start going up, and once the RPM's were raised the temp dropped drastically.

To me low RPM's would mean idling, and slow moving traffic. The is the point where the condenser fan would most likely kick on, and it is. The only thing is that it's pulling hot air from the engine bay rather than pushing cooler air into the engine bay.
 
J

JohnB

Well-known member
Oct 18, 2007
2,295
12
Oregon
The thermostat works at idle partially controlled via water pressure. The bypass circuit can limit cooling at idle.
Only thing that could limit pressure is the pump and/or a slipping serpentine belt.
Mine once over heated because the ac pump bearing was dragging and causing the belt to slip that was also noted with a hard steering wheel(thought my pump was going bad)at idle.
Also remember once someone having cooling issues because they mixed up the hoses to the thermostat.
My Nissens has over 100K on it still working well.
 
M

MStudt

Member
Feb 6, 2017
14
0
Columbia
JohnB said:
The thermostat works at idle partially controlled via water pressure. The bypass circuit can limit cooling at idle.
Only thing that could limit pressure is the pump and/or a slipping serpentine belt.
Mine once over heated because the ac pump bearing was dragging and causing the belt to slip that was also noted with a hard steering wheel(thought my pump was going bad)at idle.
Also remember once someone having cooling issues because they mixed up the hoses to the thermostat.
My Nissens has over 100K on it still working well.
Click to expand...

That makes perfect sense to me about the t-stat needing pressure. One thing that I forgot to mention was a little more about the engine. All both idler pulley's were replaced, a new serpentine belt was installed, and I'm fairly certain we don't have anything seizing up on us. I went through each item on the engine to make sure it was OK before putting it back on. I also though that maybe I mixed up the hose, but after verifying that I'm confident they're on correctly.

I should have an answer by this weekend as to what's going on if anything is going on at all. In the mean time I'm going to look into a low RPM auxiliary fan with a bypass switch on it.
 
K-rover

K-rover

Well-known member
Jan 15, 2010
2,179
69
Raleigh, NC
JohnB said:
That was OE until a few years ago think it was 210. Still not available from parts distributers like IMC maybe WP has them IDK
Click to expand...

Atlantic British sells a warm weather t stat that isn't a 180. I went with the grey OE from Rovers North
 
M

MStudt

Member
Feb 6, 2017
14
0
Columbia
There are a few places to get the soft spring 180. The one I picked up was from Lucky 8, and it's part number PEL500110GEN. This is the second soft spring t-stat installed in the last 500 miles so we can rule that out.
 
M

MStudt

Member
Feb 6, 2017
14
0
Columbia
I was really hoping to get some insight on this issue, but nothing yet. Drove the Rover today for a short distance on the highway with the AC off, and temps were over 230 degrees.

New Parts:
*180 Grey stat
*Hoses
*Temp sensors
*Nissens radiator
*Water pump (5K on it when put on the new engine)
*Viscus fan
*AC condenser fan
*60/40 water/coolant mix
*Water Wetter
*Overflow tank
*Throttle body heater

Any help would be greatly appreciated.
 
stu454

stu454

Well-known member
Dec 15, 2004
5,407
61
Atlanta, GA
Agreed with the possibility of a bad (new) thermostat. Not to lecture, but realizing that new parts aren't necessarily good parts was an eye-opener.
 
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