Overheating?

papaindigo · **Posted:** Sun Jul 28, 2013 12:33 pm

Lancer - check back on my post regarding the mechanical fan on cold startup. In theory if the vehicle has been sitting a long time the fan will spin with the clutch at least partially engaged at first startup and then as the fluid in the fan clutch is distributed, hence the clutch more fully disengages, the fan spin slows down and apparently becomes less forceful. Also in theory once the clutch is fully disengaged one can stop the fan spin with a bit of rolled up newspaper.

How true the theory is I don't know. What I do know:
1. I just cranked up my CRD after sitting for several days and the fan spins pretty fast but I don't have the feel that the clutch is fully engaged. About the best I can say is the white nylon fan is a white blur in motion and cannot be stopped with a rolled up newspaper. I did not attempt to run the vehicle a while and recheck.
2. I do know that there is enough inherent friction in the clutch with the fluid fully distributed for the fan to turn but how fast and how forcefully I don't know.
3. I did run for a while with Kap's fixed fan installed and I can tell you that the fan "drone" was audible and noticeable at around town speed/rpm say 35-45 mph and 1,500-1,800 rpm. If you paid attention it was audible but not noticeable at hwy speed say 62 mph and 1,800 rpm. Based on that I would speculate that with a correctly calibrated temp gauge and a good Hayden fan clutch that the fan clutch should start to engage at about 200-205F on the gauge (about a hair left of or at dead vertical which equals an air temp off the radiator of about 170-175F) and probably is fully engaged when the temp gauge is 1 or 2 ticks right of dead vertical. IIRC a clutched fan has some slip in the clutch so that it does not spin quite as fast as the fan base so would not expect a clutched fan to spin as fast as a fixed fan BUT I would expect an engaged clutched fan to move a massive amount of air and produce enough noise to be quite audible at the speeds where you had a heating problem. Long winded way of saying if nothing else works I'd wonder about a bad Hayden fan clutch although there are folks over here that run with no fan at all in hotter temps with no overheating.

Not much help I suspect but wanted to get the comment out there.

Lancer · **Posted:** Wed Jul 31, 2013 9:30 am

OK, the coolant flush and refill has been done. The mechanic - a decent man who's worked on my KJ many times (servicing etc) over the past 6 years told me that a lot of "muck" came out. He then ran the engine for 3 and 1/2 hours - no overheating. He'd checked the fans and fan clutch and said they were fine, but I took it for a good run to get the engine thoroughly warm and firstly the temp guage sat just under the usual mark and secondly, the engine fan was spinning at a good rate of knots. I tried the "newspaper" test, and the fan belted the hell out of it - so it was definitely engaged! The front of the rad was cool - unlike the other day when it was definitely hot. The a/c fan had not engaged, but then the temps have dropped over the last couple of days by about 10 degrees C, and I hadn't switched it on. I did switch it on the other day, and as I may have said, the fan came on about 30 secs after the ac was engaged, so as far as I can tell, that's fine too.

He did check the thermostat, and that seems to be operating normally and doesn't need replacement.

He had no idea about the brake pedal issue as (of course) it was fine for him while he was testing it. He couldn't find any issue with the system, vacuum or other controllers or with the calipers -all of which seemed to be operating normally. I will replace the fluid anyway at the next service, but I may have to treat this as the sort of idiosyncracy that develops in any vehicle you've had for a good while. In fact, every "vintage" vehicle owner I've ever met will boast of his vehicle's idiosyncracies and will describe them as part of the vehicle's character - no matter how bl**dy inconvenient they may be!

Hopefully my overheating problem has been solved by the flush and refill, and as I said, I'll be replacing the brake fluid anyway in a month before the next service is due. I'd like to thank you all for your help and suggestions, and I hope that this thread and it's contributors may help anyone else with overheating symptoms.

Adrian

papaindigo · **Posted:** Wed Jul 31, 2013 9:39 am

Well the "muck" in the system certainly could have caused your heating problem. On the brakes a random neuron fired and you might want to take a look at the "flex" lines that connect the hard metal brake fluid lines to each brake assembly on the wheels. There have been some posts to the effect that these lines can visibly swell and cause the brakes to do odd things. Solution is to replace the bad line(s) and bleed the brakes. Just a thought.

Lancer · **Posted:** Wed Jul 31, 2013 9:45 am

Good point - I was thinking about fitting braided lines - I always fitted them to my bikes for the reasons you mentioned, and the original lines are probably starting to feel their age! Thanks for the thought!

Auberon · **Posted:** Wed Jul 31, 2013 1:53 pm

Hope you've had the joy you deserve mate. It sounds like you may have it.
If this story can be born with as it may serve to help those new to the forum.

I am in no way questioning Papas' suggestion to Lancer re the brake line aspect given all the other issues that have appeared with these vehicles but for lines to be yielding so much that they cause erroneous engagement? It did, however, prompt the story. Please forgive me and I would sincerely add that Lancer took advice on board and dealt with it in a logical way.

The moral of the following story is Keep It Simple St___d.
Other car is a Ford falcon from 1997 that currently gets very hard use from well outside Sydney to Mascot airport every working day (140 -150 km of which only 15 to 20 is an easy country lope) in the very worst of traffic in a the hot and humid seasons Sydney always offers. I know it only weighs 1750 kg- slightly lighter than the KJ.

A while back we had brake issues. A worn MC. I do realise Lancer hasn't done anything like that but I do hope the new members will bear with it and reading it. With 255000 + km on it I then had repeated brake issues with not being able to keep it air-free even with the correct MC bench bled every time followed by proper installation procedures followed. Every weekend the brakes pedal would be going right to the floor. I felt the best course of action was to repeatedly bleed the air from the system and all signs and symptoms pointed to faulty MC. I was sure [b]I[/b] was missing something.

I repeatedly bled it with the most excellent Pheonix system, also manually, by gravity, with helpers without helpers and one man systems etc. I cross bled, disconnected the lines at the MC and bled front to back , back to front etc locked off the mc to isolate each circuit with positioning of the brake pedal EVERY b-----y thing I could think of. The problem was air and there were no apparent leaks. No 2 ways about it.

This was all because I made the mistake of purchasing pre-assembled MC's which worked well enough for about a week, maybe two and then ffffft - pedal to the floor. AIR again. I installed three units in fact and I could not fix it.

Then I went back to my training and thought back to basics rather than clutching at straws - looking for anything to blame. I then rebuilt the MC myself with a good quality rubber kit which definitely remedied things and it is still remedied after a further hard 85 000 km.

These automotive forums offer much good but one thing they have have done is encourage me to expect the worst that can happen- if you like they teach you to catastrophise - even one trained to look deep into the simple will, if they read enough grow to expect the expensive and the complicated.

I now know better and take them with the mirth and amusement they offer. Many of us have short arms and deep pockets with just loose change at the bottom, myself included.

[color=#FF0000]Apologies for the long story but the Moral of the tale is KISS [/color]mate.

I went through every convoluted possibility and ignored the patently obvious.
Please don't do the same.
Hope this is OK Lancer - let me know if you want it removed. You know I won't be worried if you do.

Lancer · **Posted:** Wed Jul 31, 2013 2:35 pm

No worries mate - illustrative anecdotes are never a bad thing. Its like law exams - people forget that there are a lot of marks given just for stating the basic stuff before moving on to the clever bits and they jump straight for the clever bits and wonder why they didn't do as well as they should!

Overheating?

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