Outer Limits 4x4 Board

G'day All,
Yes, I'm back with yet another problem for you great people to solve, .

Here's the issue;
I can drive around at 80km/h all day without any problems. But, as soon as I creep the speed up to 100km/h, my temperature rises up so bloody quickly it's at the Hot mark within about 10 seconds. Back off back down to 80, and by the time you're at 80, the temp is back down to normal!!

So, seeked a few peoples opinions and tried to do some trial and error. It came down to 2 things. First thing which I tried was to take the radiator out entirely, and flush it and clean out any rubbish which has found it's way into the radiator. Didn't hold much hope that it'd solve the problem but thought it can't hurt anyway..... And as expected, it didn't solve the problem.

Next thing I tried was to change the thermostat. Seemed more logical given the temperature sender is right above the thermostat, so thought it'd be the problem for sure. Found me a nice new thermostat (did someone say Daihatsu Rocky? Ahh yes, you did, hold on one second while we just triple the price for you!), took the old one out, nice new gasket on it, and all back together. Topped the coolant back up and off we went for a test drive.

Well, I don't quite know if 'interesting' would quite fit the results of the new thermostat, . 80km/h, no worries at all. 100km/h with the air con off, she went well. Air Con on, hmmmm, she climbs back up, but not as quickly. Air con back off again and she comes down to just above normal. So thought I may as well drive along with the air con off, just to see how she went like that. No probs, she still climbed a little, and back down, but not like it was before. Then came to a big hill, and sheesh, the temp nearly went through the roof again. So pulled over and by the time I'd stopped, the temp was back to normal again. (Sorry if this is getting a bit long winded).

Just out of curiosity, I sat there stopped, and took the rev's up to where they'd be at 100km/h. Think it was there for about 5mins, and the temp guage did not move one bit. It stayed on a perfectly normal temperature.

The drive back to Isa, the temp was about normal nearly all the way back, even with the air con on. Think a couple of times it did warm up slightly, but wasn't long before it went back to normal.

So now it's got me bamboozled. I can only think of 2 more issues it could possibly be. 1 is the temperature sender or the guage itself. The 2nd one, and I consider it the absolute last thing, is the clutch thingy in the cooling fan. The fan appears to be operating normally though.

SO, ANYONE HAVE ANY IDEA WHAT MY PROBLEM IS!!!! Pleasssssse!



Cheers in advance.

Floody

my rocky ute does the same but i have tryed new rad new fan bigger rad now i just do not push it over 110 whith my tralior on .no tralior no hot mine is turbo diesel some one told me to flush the engine with some oil product to un glogg it????? lets here what u all got to say

How old is your water pump? also might be the temp gauge or sender.

I would be leading towards the clutch fan or injection timing.

Just some thoughts:

- free revving the engine at same revs as 100km/h doesn't really prove anything as there is no load on the engine.

- is it a genuine or aftermarket thermostat? http://carl.outerlimits4x4.com/viewtopi ... thermostat

- do you have a viscous hub fan-> is it locking up properly or giving up under higher loads?

- what sort of condition is your radiator in? I ended up buying a new one for my Feroza and it did improve things.

- you'll probably find it will be a combination of small things causing your problem, rather than just one specific issue.

- have you checked the belt tension on your water pump pulley?

Is it a diesel or petrol engine? Running ignition timing on a petrol retarded will cause over heating (I've proven that with my Feroza ) and I believe incorrect pump timing on a diesel can cause overheating too?

Thanks for the tips so far. To answer a few questions:

- It's the 2.8L Turbo Diesel engine.

- Aftermarket thermostat, however the one before it was a genuine one, and it was the worst of the 2 results wise.

- It's a viscous hub fan. Appears to be locking up properly, and functioning correctly. However, might have to fiddle a bit more with that one. Pretty confident it's working though.

- Waterpump is only about 1.5 years old. I am just about ready to take it off though and just check there's no rubbish stuck around the impellor. Unfourtanately takes a bit of time, and won't be able to do it this weekend.

- Radiator is in pretty reasonable condition. Doesn't look like it impedes water flow, or air flow.

- Haven't checked the pump pulley tension, so might give that a go today.

- After a bit of thought, I ruled out the guage and the sender, mainly because at the normal temps and when the speed isn't above 80km/h, it operates normally.

- How do I check the timing of the pump?? Is it a job I can do myself, or off to a mechanic? :(

Thanks for the tips. Keep them coming!

Floody

Floody_1985 wrote: - How do I check the timing of the pump?? Is it a job I can do myself, or off to a mechanic? :(

A diesel tuning specialist is your best bet for this Michael, you could get it tuned and dynoed to make sure everything is running sweet.
Mine's going to one soon to tweak the pump and make it run perfect.

Have you tried no thermostat? Just to rule it out completely.
They are the crappiest thing in existence.

- Aftermarket thermostat, however the one before it was a genuine one, and it was the worst of the 2 results wise.

I take it by saying "the one before it was genuine" you mean the old original one fitted from the factory and NOT a new genuine one?

I still wouldn't discount that being an issue- especially after my experiences... I tried two after market thermostats (Tridon and Dayco) and both weren't as good as the genuine Daihatsu one I ended up paying out for. In fact the new radiator and new genuine thermostat have cured my problems- I still had overheating issues with both aftermarket thermostats.

Are you running standard boost with your turbo- have you checked the pressure levels lately?

Was it a genuine water pump too? I've fitted two aftermarket ones to my wifes Excel and there are some dodgy designs out there that are NOTHING like what the original pump looks like (totally different impellor shape/ design.) That could make a difference too?

Yes, you're correct in interpretting my jibberish Murcod,

I'll give a genuine thermostat a go (the one I've got in at the moment is a Dayco), see what results that gives me.

The waterpump, don't think it's a genuine one. However it's been working fine up until now.

Standard boost, but haven't checked the pressure levels lately.

Floody

Have just taken the waterpump off and inspected it. In perfect condition on the inside.

So that rules that one out!

Floody

i put all new items you are talkin about on my f77 and all diahatsu even new rad but it still gets very hot above 105 kms. if you drive 100kmph all day no problems . i wondar if it is because at over 105kmph it is on boost all the time and that is y it gets hot. ferozas dont run as hot as diesels do my feroza f310 never got hot and had a 75% blocked . but i have noticed that we all have different little bugs at times but my rocky f77 is a pane in ass

Ferris, don't think that would matter, having it on boost all the time. I've put about 80,000km's on my Rocky since I bought it in late 2004. In that 80,000 is about 25,000km's of highway driving around the entirety of Australia, sitting on 100-110km/h all day every day. Problem has only arisen in the last couple of months.

Floody

floody lets work this out as there has to be some sort of small thing to fix this i have spent about 2gs on this sofar. it might be better to put my 2nd motor in and see if that makes a difference .but that is a big job

Have you ran it with no thermostat to rule it out completely?

Not real keen on operating a diesel without a thermostat. Mainly because it needs to be up at operating temperature, otherwise damage can be done to the engine. And I'm not taking the damn thing out when it's up at normal temperature, .

Going to try a genuine thermostat first. Right after I get my failed alternator fixed first, . 1.5 month alternator and it's already shot!

Floody

Floody_1985 wrote: Going to try a genuine thermostat first. Right after I get my failed alternator fixed first, . 1.5 month alternator and it's already shot!

Floody

that cost you a small bank

Pity Rocky and Feroza alternators aren't the same because I've got a spare in the garage.

Good luck!

How much is the genuine thermostat costing you? My Feroza one was $54- ironically I spent more than that trying the Dayco and Tridon ones first..... which have since been binned!

The good thing about going genuine is you get the gasket included and don't have to fork out more $$$ for a gasket on top of the thermostat.

Couldn't believe it, . The genuine thermostat is cheaper than the Dayco one I purchased!! It's on it's way. 10 days from Japan.

The alternator, errrrm, ... it was the damn fuse in the voltage regulator. Since when have they put fuses in the voltage regulators....

Floody

Was actually just about to swap the themostat out of my N/A Rocky tommorow. Have put it off tho because i've got some other stuff to do. On my second Dayco one now. Not getting another one. It runs to hot. All the aftermarket ones are overpriced rubbish.

The problem i'm having with the genuine ones tho' is they jam shut in really cold weather causing the temp gauge to go off the dial almost (all be it momentarily).

My next plan of attack is to put one of the near new daihatsu ones back in and drill a couple small holes in the outer ring. Hopefully this will compensate.

You can't just completley remove the thermostat unless you block off the bypass port. Otherwise the radiator won't get the full flow.

I've battled with cooling issues on my rocky for years now. It seems to be a pretty common issue. Just don't let it get too hot otherwise you can say bye-bye to your head. It may not crack now but the damage is done. All thats needed is time.

Cheers

tabrocky wrote: The problem i'm having with the genuine ones tho' is they jam shut in really cold weather causing the temp gauge to go off the dial almost (all be it momentarily).

Are you running decent coolant because the coolant also lubricates seals and should stop that happening.

I know my Dayco one I tried was obviously jammed shut and the needle went up to 3/4 before suddenly dropping right back..... It only did it once? All the Feroza aftermarket ones I tried had very small openings compared to the genuine one. I ran without a thermostat for a bit and it didn't overheat (but agree about the port needing blocking.)

Don't get too carried away drilling holes either as I tried that with one and it wouldn't reach operating temp on cold mornings afterwards. I'd only drilled two small holes! Bl**dy thing still overheated on hot days though?!

Would anyone believe me if I said I went for another long drive yesterday, with the air con on the entire way, and could not get that damn temperature needle to move!!

I don't know what I did, but it is running perfectly now. Even a touch cooler than before. Do some thermostats require a bit of a run before they work effectively??

Either way, the genuine one is still on it's way.

Floody

Was it a cooler day? I only ever had problems on 30 plus degree days. The aircon on was always a killer for temps rocketing on mine too!

Was all of about 1 degree cooler. Bugger all temperature difference.

Floody