Overheating

[peteabbott]

Very topical this overheating thing at the moment. Got a lower temp stat for mine and did not help much as she still overheats ( 1.9D) Took out the stat and ran it without, still hot but took a bit longer to get hot. If I turn on the heater full blast, phew, it does cool her down so diagnosis is a blocked rad. Tried rad flush but this new health and safety safe stuff does not seem to have any aggression so did not shift anything. (Nitromoors paint stripper does not strip paint anymore because the H & S have taken the caustic out of it) Anyone been succesfull with a rad flush product ?

[ermie571]

Sigh... once again, viscosity is relevant, base is not.

.

sorry Adrian, I was only trying to help! We are NOT all knowledgeable, and I for one don't understand what you mean by Base....unless its a reference to semi-synthetic. And if so, you are saying semi is fine....well, maybe for you, but kev below recommends mineral, as do the long timers with these buses. maybe semi is fine....but I'm not gonna take the chance!

ALWAYS on this club mineral is recommended. Tony doesn't know what oil was used...all I did was pass on what I have been told, and admit to what I couldn't remember. So, rather than sigh and whinge, why not put the viscosity down??

sorry rant over

Em


E D I T: oooo I was in a mood, wasn't I? lol
Not like me to let rip on the forum. Anyway, apologies for the rant...Adrian and I have spoken over pm, and we are friends again xx

xx

[Sir Brixalot]

I've been having major problems with overheating, I put it down to old pipe/water tanks splitting but they were a symptom not a cause. I have just found that part of the the thin pipe that runs around the top of the engine was blocked - its an easy thing to check.

[Tony Tone]

So, am i right in thinking that the oil light may be doing the fluckering thing at islands as the oil needs to be a tad fatter ?.

[Tony Tone]

And a big thanks to em for suggesting stuff it might be .

[ermie571]

Tony,

I am no expert in this field....but flickering oil light has, I beleive, had posts about ensuring the correct grade. It may be the correct grade in there....but few only a few quid you can empty and make sure the correct grade is in. The semi-synthetic vs mineral debate will rumble on and on.....but it would appear that the viscosity is the most important bit I guess.

JUST for your own peace of mind, and a known starting point, an oil change is an affordable and quick job to do. So if it continues, you can say...Its not the oil, I know. I drained it, changed the filter for a MANN one, and gave it XX-XX oil.

Em
xx

oh - and you are welcome!!

xx

[Tony Tone]

And the next jolly sensible question is ....... If i do have semi or synthetic ( i dont know what i have in there) and i need to top it up , can I ?. Im currnetly 200 or so miles from home in windy Dawlish
so an oil change isnt really an option till were back. That said, oil is 3/4 full so im guessing i should just leave it all alone until on the relative safety of my drive ?.

[ermie571]

just be careful. If the buzzer gets persistant...STOP and call recovery. x

Em
xx

[Tony Tone]

Well thus far, no buzzer at all, just the occasional flicker of the oil light when pulling to a halt at islands. Apart from that, its running ace

[AdrianC]

Adrian and I have spoken over pm, and we are friends again xx

Were we ever anything but? <hug>

One thing's for certain, though - any lubrication issues (low pressure at idle) are not a cause of the overheating, but far more likely to be a symptom of it, due to the oil thinning out too much when it gets hot, allowing too much pressure to be lost through (at a guess) worn bearings.

Tony - yep, mineral and synth are miscible, no problem.

[AdrianC]

Very topical this overheating thing at the moment. Got a lower temp stat for mine and did not help much as she still overheats ( 1.9D) Took out the stat and ran it without, still hot but took a bit longer to get hot.

A lower-temp (or no) stat won't make any difference to overheating. All it does is cut the rad out when the coolant's too cool. Too cool a 'stat - or no 'stat - will give you more engine wear and worse fuel economy, due to the engine being lower than normal running temperature.

[kevtherev]

lower coolant temp will give a higher oil pressure at low rpm where most wear occurs
High oil pressure is encouraged.
coolant temperature is the driving factor to oil temperature they are inexorably linked in a water cooled engine.

To negate the cooling systems command of the oil temperature, one must cool the oil separately.
Cooling the oil separately to 81 deg will significantly improve engine life.

[AdrianC]

High oil pressure is encouraged.

Up to a certain point. Beyond that point, you're wasting power and fuel for no lubrication benefit.

[kevtherev]

Maintaining 45 psi at 3500 rpm is impossible with the WBX cooling system even with an 80 deg C stat... mine still dipped to an alarming 25 psi at cruising speeds.
Ideal oil temp should be around 225 deg F ensuring a very good pressure to feed the bottom end

I think you are mistaken regarding power, the oil pump pumps regardless, the oil it pumps is not cold it's allowed to get to working temperature as normal then it's kept there with the oil cooler and cooler thermostat and not allowed to rise causing thinning and loss of pressure.

lubrication is king for prolonging engine life. Your bottom end clearances are quite large and when your driving hard the more pressure present the more protection you have.

[peteabbott]

Yes mate, thanks for the reply.I was on a 50mile run and the temperature rose.....a lot. I thought o dear the stat must have failed to open. I then turned the heater full blast and this bought the temperature down to nearly normal, yup must be the stat and no circulation to the rad. Bought a new stat (lower temp for the summer I thought) But decided to give her a run with a bit of useless flushing stuff without the stat and the temperature still rose the same, heater matrix on and it cooled her down again. I have very short arms and very deep pockets so I was kidding myself that the rad was O K Garden hose had a lot of resistance when I tried to flush water through it so a new rad it is then. Jesus I hope this all makes some sort of sense and I haven,t gone completely loopy.