Questions about cooling/power

[Blitzpatrollie]

Hi guys,

Okay this weekend I installed a snorkel, myself. Wow, what a job. Me and my fat little fingers don't fit in everywhere. Anyhow, I was going to take my troll to Graham today, but my wife's Kia is in with gearbox trouble. So anyway, regarding my previous post about no power on the patrol on uphills, I decided to tackle a few issues myself and see how I go:

- Install snorkel
- Flush radiator with radiator flush, drain all coolant and fill with new coolant.
- Remove front muffler and check for blockages

This took me ALL of this weekend and I don't think my shower floor will ever be the same again.

Anyhow, this is what I found:

- After snorkel install, patrol seems faster out of the blocks, but no major impact on uphill power (or lack thereof). Also, check engine light came on. I think this is because of the silicone gasket maker I used and failed to wait for it to cure properly. Reset fault code this morning and no more light.

- Flushed radiator, at first got worried because the engine was up to temp, but right radiator hose was still cold. Heater in the cabin also still blowing cold. So cut engine, opened radiator cap, lots of air escaped, topped up, then ran again. After the third time, all hoses warmed up as they should. After a few mins, the radiator stayed full as well, so test drove it up and down the hill here near the farm. No move on temp gauge, when I got back (+-8km), radiator was still full. Noticed more of an improvement in performance than the snorkel, better on uphills. Might also be because I drove it hard. Time will tell... Also when I flushed the radiator, I didn't notice any gunk coming out the drain at the bottom. Assume radiator is okay.

- Removed the front muffler (free flow exhaust), no blockage. Will take it in to have the rear muffler checked as well. Also there are no gaskets on the exhaust connections and some dirt has caked up between the flanges. I am going to stick my neck out here and say the exhaust MUST be leaking. I cant really see how this will make a huge difference, but will have it checked anyway.

Anyway my questions are:

1. Why does the right hand side (facing engine from front) of the radiator get warm while the left stays cold? This happened at first while flushing, draining, running etc.
After final fill up and test idle, both sides of radiator got warm. Is this a sign that the thermostat is working? Does the cooling system just allow flow into the other half of the radiator when the thermostat opens?

2. My viscous fan from cold start thru normal driving, idling etc, never ever changes speed independently of the engine. It never slows down and only speeds up with the engine. I start up cold and idle, then as the engine comes up to temp the fan should speed up, but mine seems to run at engine speed all the time. Is this an indication that the viscous coupling might be stuffed? Or maybe warm temperatures in the radiator all the time stiffening the gel inside and thus engaging the fan?

3. What else can you guys think of that I might check?

My troll has branches/extractors with asbestos insulation, and free flow exhaust. Have done the power valve actuator mod. No other mods or chip.

Thanks chaps!!

Gavin

[Peter Connan]

Gavin, firstly the thermostat:
When closed, water will only circulate in the engine. Some heat will "soak" into the lower end of the radiator, but not all the way through.
When the thermostat is open and there are no blockages, there should be less than 5 degrees difference between the inlet and outlet of the radiator, so that sounds good.

Now the viscous: the fan will never turn faster than the engine. What the viscous does is to partially disconnect the fan, so that when the engine is running but the engine is cool, the fan will turn more slowly. The disconnect should be audible. IE you should hear the fan disconnect about half a minute after first starting the engine in the morning. If you don't hear this, you can try feeling how hard it is to turn the fan (with the engine cold), then start the engine, run it for a minute, switch it off and feel if there is a difference. It should be easier to turn the second time.

[Blitzpatrollie]

Hi Peter,

Great okay so you think my thermostat is okay?? I didn't quite follow the whole 5 degree difference thing?

My viscous fan doesn't make any sound at all. From startup it just spins along with the engine, there is no connect or disconnect that I can hear. As a side note, while flushing and cleaning the radiator, I did note that the idle revs kept dropping lower and lower til about 500rpm. I ofcourse thought that this my engine overheating... (paranoia). Do you think this drop in revs was the ecu compensating for the lack of resistance on the viscous, thus lower the idle revs since the higher revs are not necessary to keep the fan turning?

Gavin

[Chris Skinner]

Its good to make sure the system is bled properly - there was a recent post about a guy who overheated his engine because he did not know there was a special air bleed valve on the cooling system...

[Blitzpatrollie]

Yep I read that too and made sure to open it up and bleed it while filling :)

[Peter Connan]

Your thermostat sounds OK, but I am concerned about the viscous!

[Blitzpatrollie]

I tried a test yesterday, i poured boiling water over the viscous and flicked the fan, i turned about 1/3rd of a turn. Waited about 2 hours, then flicked again and did just more than 1 full turn. Maybe semi functional?? I think i'll replace anyway?

[Tinus lotz]

Have you got a overheating problem? Remember the heat gets taken via the shaft and takes some time to react . You do need to hear a positive connect and disconnect is more on the volume of air moving

[Blitzpatrollie]

Hi Tinus,

No i dont have an actual ovetheating problem, but am pondering on whether running too hot is costing me power. The real issue im after is the lack of power on uphills... Im just checking cooling system, installed snorkel, checking mufflers etc to see if i can get some grunt back. Machine already has branches and freeflow. Branches make under bonnet temps very hot!!

[Tinus lotz]

IMHO branches make more problems than anything else on a 4.8 the gain in power is nearly nothing but thats just me . Did you try a fresh feul filter ? Did you check your feul pressure up to correct speck? Check with graham but it sould be a constant 2.2 bar . The most power problems are related to worn feul pumps ,but it will make sence to let graham look at that you dont want to start charging pumps ect unnecessary. Better measure and make sure. The scan tool also helps then you can see what you are doing