Overheating Y60 4.2 petrol Patrol

[AndriesS]

If you include a correction for the thin air the compression is not all that bad.

the 4.8's fuel injection does make for easier driving than a carb/dizzie with high CR but when it breaksdown........

I've had good experience with the guys in Booysens Road in Jhb next to the ceramic coaters (I think it is Sartor Brothers Engineering (Pty) Ltd) They did not do machining for me but helped to measure a crank and gave advise which I felt was reasonable and sensible.

When you do the engine consider balancing the rotating parts, makes for smoother revving

[Mrowka]

Two more things to look at are ignition timing and your fuel injection unit.

Ladies and Gentlemen

Ever since I bought my 1996 4.2 nearly 2 years ago it has had a tendency to overheate under certain conditions. These conditions are primarily when driving relatively slowly but with the engine still working hard at lowish revs, such as up long, steep hills or through deep sand. In these conditions the temperature will continue to rise untill the car boils or you stop to take a rest.
the following steps have been taken to try and fix the problem, but without success:
1) The radiator was removed and taken to Silverton Radiators in roodepoort, where it was dimantled, cleaned and a small leak repaired.
2) The thermostat was replaced (it was found to be stuck partially open).
3) The water pump was removed and checked, but seems to be fine.
4) The cooling system has been flushed several times.
5) The viscous fan (which was busy breaking) was replaced by 2 14"electric fans. The fans are in a cowling and switch on sequentially, the first at 95 and the second at 102 degrees. The system also has override switches that can be used to switch the fans either on or off. (The reasoning behind this modification was that at the low speeds at which the problem generally occurs the viscous fan is turning relatively slowly and therefore is not of much assistance)
6) The mixture has been richened slightly and the timing etc. are regularly checked.
7) The correct anti-freeze mixture has been restored several times.

Most of the major repairs described above have improved the situation, but the problem persists and is too serious to be ignored. During the above work the following additional factors have come to light:
1) The system was operated without anti-freeze for extended poriods, as some of the smaller steel fittings have had to be replaced because they have rusted through, and there was generally quite a lot of rust present in the system.
2) The radiator was repaired with stop-leak or Bars Leaks or some similar solution. I have been told that this stuff can coat the engine internals thereby reducing heat transfer and possibly even block some of the smaller channels in the engine, and that it cannot be succesfully removed with the engine in one piece.

It is therefore my intention to remove and dismantle the engine, and have the block, head and any other suitable components acid-cleaned before re-assembly. The major reason for this is that I am scared that there may be areas within the engine that are not being cooled effectively and that are thus even hotter than the temperature gauge suggests.

I thus have several questions for the learned and experienced people present on this forum:
1) Where can I find gaskets etc. (the local spares shops have been unable to source these)?
2) Should I replace the oil and water pumps?
3) Are there any modifications that I should carry out at the same time? (I would also like to increase the power output somewhat but am operating on a rather tight budget)

Any recommendations would be gratefully accepted and carefully considered. ALso, are there any glaring problems I may have missed?

Regards and thanks in advance
Peter

[Peter Connan]

Thanks John

Is driving without a bonnet legal? I would like to try it, but it would obviously be difficult if I can't get to a trial or something without it.

Grant and Jeanne thanks for the tip on Masterpart, they do indeed and for less than R1k. Grant I am one of the minority who always tackle an obstacle as slowly as possible, as I beleive that the combination of speed and rocks breaks stuff, and since the patrol's low range is higher than most that sees me tackling most rocky climbs at less than 2000rpm.

Thanks for all the help so far guys.

Cheers
Peter

[Peter Connan]

Hello Guys

Attached are some pictures of my water pump, as I had to remove it in order to try and identify the correct replacement.

wp7.JPG (353.08 KiB) Viewed 1901 times

wp4.JPG (341.07 KiB) Viewed 1901 times

wp3.JPG (354.3 KiB) Viewed 1901 times

I do not beleive the pump is the problem, am I wrong?

Thanks
Peter

[David]

Doesn't look too bad to me either even though it is pitted. I assume the impeller didn't come loose from the shaft (Grabbing the impeller and pulley side and turning in opposite directions)?

Take it with when getting the new one and compare - maybe there is too much play?

This has actually got me thinking - Is this waterpump the original? (I'm looking at all the silicon sealer) - How tight does the impeller fit in the space where it bolts in - If the impeller is too small it will have a major effect on the water flow?

[Peter Connan]

Hi David

The impellor and pulley flange are both very tight on the shaft and I very much doubt there is any slippage. Wether the pump is the original there is no way of telling, but the bolt holes and casting edges all line up well and according to my manual silicon sealer is correct, there is no gasket. However as you have pointed out there seems to be a hell of a lot of space around the circumference of the impellor. Perhaps the casting/casing is correct but somebody has replaced the impellor with something else?

Unfortunately it is not as simple as taking the old one along to the spares shop, as that is in Cape Town and i am not.
Does anybody know what the diameter of the impellor should be, or does anybody possibly have a spare waterpump that he can measure?

Thanks
Peter

[Herrie]

Het jy al 'n manual gekry? Daar mag inligting daar in wees - ek het nog nie gekyk nie!

[Herrie]

Het gou in die manual gekyk - geen mates vir die deursnee van die impeller nie maar wel hoe ver hy moet uitsteek (9.4 - 9.9mm).

Wat baie interessant is, is dat hulle jou wys hoe om die pomp uitmekaar te haal en die bearing en seel te ruil - dis die eerste keer dat ek sien dit is moontli!k om te doen!

[Peter Connan]

Dankie Kobus

Snaaks genoeg se my manual dat mens nie die waterpomp kan onderhou nie, net vervang, maar dis ook nie die eerste keer dat ek sien dat manuals met
mekaar stry nie. Ek gaan nog jou offer vir 'n CD-manual opneem, ek kom net nie by jou uit nie.

Dankie
Peter

[AndriesS]

Must agree with David, impeller looks ok but does look a bit small.