Improved Engine Cooling?

[evilfij]

I have had three D90s and a ROW 110 V8 and if everything is in working order, they cool fine. I would make sure the fan clutch is working properly first and then check the radiator overflow tank cap. Given that it is happening at low speed, odds are it is the fan clutch. Next on the list is a bad radiator, but they are dear at $600 new.

 

[R_Lefebvre]

Do you even know what a Land Rover looks like?

I've only spent time with a 2007 MY Defender. It had radiator shrouding. My Disco also had shrouding, some of which got removed when I installed the bumper.

 

[michaelgroves]

Is the cowl all properly in place, no bits missing?

Edit: Never mind.. didn't see there was a second page to the thread!

 

[muskyman]

I think what Hank was talking about was advice coming in the form of theory again on a subject that should be very easy to sort out.

people want great cooling but they also want to skimp on things like having the radiator recored or replacing a fan clutch.

couple things that should be looked at

Radiator flow: the combination of metals in these things cause deposits and those deposits will clog the radiator. those deposits will inslulate the inside of the radiator and prevent heat transfer from the coolent to the radiator and thus prevent the radiator from transferring that heat to the air moving across it.

the single biggest problem I have seen with overheating is clogged radiators.

Fan Clutch: the fan clutch on these is a thermal clutch. the hotter the radiator is the tighter the clutch becomes and the more air the fan will push. these clutchs fail over time and become less positive and that prevents them from moving enough air across the radiator. They are designed to release somewhat at higher RPM so that they dont explode the fins at high RPM. If they start Roaring at high RPM the clutch needs to be replaced right away. there are a number of proven none land rover replacements in standard all the way up to extreme use variants. this rating is based on how tight they are at different temp ranges. I run a extreme duty fan and at low rpm it is very positive but it still will realease and make no noise at highway speeds.

system pressure: system pressure is very important because it allows the system to raise the temp that the coolent will boil at. the pressure is controlled by the cap on the resevoir. the system can also have small leaks that will prevent the system to generate the pressure needed. the most common failures are very small leaks in a clogged radiator right where the core is soldered to the tanks. After that the expansion tanks tend to fail and leak down the pressure and allow the system to boil at a lower temp. The best way to diagnose these issues is with a pump that allows you to pressureize the COLD cooling system and look for the leaks. when the system is cold and the engine shut off the hiss of a leaking system is very easy to locate.

Flushing the system: the system should be drained of all coolent and refilled with clear water before a flushing agent is added. adding the flushing agents to coolent renders them worthless in most cases and will not disolve and cut the crud like it should. read the directions on flush chemicals and you will see this is very important. After the system is flushed is when you need to check for leaks as the crud/deposits that are in the system will often plug up leaks that should be repaired.

Bleeding the system: Air pockets in the cooling system can and will prevent the coolent from flowing correctly and this will undermine the system from cooling to a very great extent. Infact a system with air pockets in it will reduce the cooling capacity so much that it will often cause the auxilary fans to run just when a truck idles. Air can be introduced to a system through leaks or from incorrect bleeding when refilling the system. The best way I have found is to place the truck on a very steep incline and to pull the plug either in the upper radiator hose on newer models or the radiator plug in the older ones. I also like to use the snap in funnels that allow you to hold coolent well above the normal level. the weight of this coolent and the high incline will help push the air through the system and out at the front top. It is important to have the heater going at this time to allow full circulation to clear any trapped air from the heater core. I always make a point to overfill the system when bleeding and let the system purge itself down as it come up to temp then use a turkey baster to remove coolent from the resevoir down to the correct level.

In the end the Rovers cooling systems dont need modification to work in the worst hottest climates on earth, they just need to be maintained correctly with some very simple knowledge of how they function and what symptoms point to as the culprit when they start to fail. In the end many failures are a combination of condition coming together to undermine the system.

 

[Alaska Mike]

Do you have a winch or other obstruction installed in front of the grill? Do you have an oil or tranny cooler (aftermarket) installed?

I can think of many good reasons with going with an additional electric fan setup, but make sure the bones of the cooling system is sound first.

 

[michaelgroves]

I think what Hank was talking about was advice coming in the form of theory again on a subject that should be very easy to sort out.

Hank wasn't making any contribution at all, just making poisonous comments, much along the lines of your own snide sig. You can call Rob's point "theory", as indeed your own points are "theory". However, in fact, he's spot-on. Take the cowl or shrouding away from a fan, and it won't suck air through the radiator properly. Cooling will still work at highway speeds.

Please just drop the attitude.

 

[Nadir_E]

I very much appreciate all the suggestions and pointers, everyone. It looks like I need to spend some quality time with the Defender. I'll poke around with these comments in mind on the weekend and, if appropriate, post some pictures of the engine bay so all can weigh in on what is present or should be.

As for rodding out the radiator - I had that done about five years ago. Certainly possible that it needs attention again.

all the best,
-N

 

[muskyman]

Hank wasn't making any contribution at all, just making poisonous comments, much along the lines of your own snide sig. You can call Rob's point "theory", as indeed your own points are "theory". However, in fact, he's spot-on. Take the cowl or shrouding away from a fan, and it won't suck air through the radiator properly. Cooling will still work at highway speeds.

Please just drop the attitude.

yeah my post was all theory...100%

no good information there...LOL

and as far as dropping the attitude you guys seem to get to attack people without any of your posts getting questioned but yet others post go away and get editted.

 

[muskyman]

As for rodding out the radiator - I had that done about five years ago. Certainly possible that it needs attention again.

all the best,
-N

bingo if you have not flushed since that rodding that is going to be your issue.

rodding will help some but the small film of deposits left will very quickly start to seal off the inside of the tubes again.

I am not sure on the defender but the disco 1's and the RRC's tanks allow you to put a larger core in there very easily to gain capacity in the radiator. I am running a 5 row heavy duty core in mine.

 

[Scott Brady]

The reality is that some of these new members from "other" sites really do know what they are talking about, and we can genuinely benefit from their experience. We do, after all, own Land Rovers

If we show some respect for their experience (actual, on their backs on the trail, in the mud, replacing a radiator experience), then they will likely respect the more conservative rules of our forum.

I also find that engineers can benefit from listening to the guys turning the wrenches. I have had many mechanics and many engineers work for me in the past, and this is just another classic case. The mechanic standing in front of the engineer with a clearly broken part, and the engineer arguing with the mechanic that it cannot POSSIBLY be broken. Reality trumps theory most of the time.

This also does not change the rules of ExPo, where flaming and personal attacks are not permitted.

 

[Geo14cux]

bingo if you have not flushed since that rodding that is going to be your issue.

rodding will help some but the small film of deposits left will very quickly start to seal off the inside of the tubes again.

I am not sure on the defender but the disco 1's and the RRC's tanks allow you to put a larger core in there very easily to gain capacity in the radiator. I am running a 5 row heavy duty core in mine.

My Defender rad has room for an extra row.
In my Disco I added an extra row to my core but I used the old style core
[80's]. The gap of the fins is a little larger.
Also the fins on these rads seem to rot pretty easy. If they are your cooling will be greatly diminished..
As stated you rodded the core 5 years ago. Ding fries are done!
IMHO rodding is a band aid & will only buy you so much...Tyme

 

[Blueboy]

as indeed your own points are "theory"

interesting.

what points do you feel are theory?

imo, Musky is 100% correct in his recommendations on what to look for with cooling issues.

as a reference - my 109 with a 4.0 Rover V8 has no shrouding what so ever with the stock IIa radiator and it cools very well because the system is maintained for the most part in the manner Musky outlines - it has an electric fan so no fan clutch.

thx,

Jaime

 

[Nadir_E]

I am not sure on the defender but the disco 1's and the RRC's tanks allow you to put a larger core in there very easily to gain capacity in the radiator. I am running a 5 row heavy duty core in mine.

I seem to recall (he said, staring at the sun) that the radiator guy thought he could get a 4-row into it, but I'll have to check again - it's been a long time since that conversation.

Thanks for all the input! Excited to think of being able to solve this problem and thus make trail runs more pleasant for my co-driver of choice!

 

[Geo14cux]

The reality is that some of these new members from "other" sites really do know what they are talking about, and we can genuinely benefit from their experience. We do, after all, own Land Rovers

If we show some respect for their experience (actual, on their backs on the trail, in the mud, replacing a radiator experience), then they will likely respect the more conservative rules of our forum.

I also find that engineers can benefit from listening to the guys turning the wrenches. I have had many mechanics and many engineers work for me in the past, and this is just another classic case. The mechanic standing in front of the engineer with a clearly broken part, and the engineer arguing with the mechanic that it cannot POSSIBLY be broken. Reality trumps theory most of the time.

This also does not change the rules of ExPo, where flaming and personal attacks are not permitted.

Again! Ding fries are done!
Most people on this site are & were on ther sites before so-um-ah-Hmm-ya-LOL! So the "other site" thing might be a wash.
Its hard to beat experience. Sounds like Muskyman has been under a few trucks before.

 

[kellymoe]

Is the cowl all properly in place, no bits missing?

Edit: Never mind.. didn't see there was a second page to the thread!

That may be part of it but I have been running without a shroud "cowl" for 5 years without issue. My issue was simply the expansion tank cap fortunately.