Jago Swizz
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 posted on 23/4/05 at 07:47 PM |
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xflow overheating
Has anyone had overheating problems with crossflows with no obvious cause?
I've had the car 6 months. It ran v.badly so its had an engine service, carb rebuild & rolling road set up. Rolling road guys think it has a
non-standard cam as it still ticks over lumpy with high hydrocarbons, but is ok further up the rev range.
It runs very hot. I've removed the spotlights that blocked the grill with no effect. Changed the thermostat, no effect so removed the thermostat
in the end!
Replaced the water pump & flushed the system with no obvious flow problems.
Always runs at high temp v.close to elec fan kicking in. Fan activates at will in traffic once the engine is hot.
With steady driving around 30-40mph temp hovers around 3 quarters on the gauge, going right up when on the motorway.
There is no coolant loss. Similarly the oil is clean. Removing the rad cap gives no indication of pressuring.
I haven't rechecked the ignition timing yet, incase the rolling road guys got it wrong. I'm running on 97 octane unleaded. Unsure if the
head has been converted but as its a different colour (blue/green) to the block(red) it may have been converted to unleaded.
Any ideas???
This is why i'm thinking of the CVH (see recent post)!
Swizz...
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viatron
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| posted on 23/4/05 at 08:18 PM |
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Are you absolutley sure its overheating? how about a faulty sender or gauge? Try hiring an infra red thermometer with which you can get acurate temps
on the block.
If it is not a gauge problem then have you checked the water pump? some cheaper recons used a folded steel impeller that is not nearly as efficient as
the proper cast impeller, in some cases it even comes loose on the shaft.
Have you tried fitting an oil cooler? i had a similar problem a few years back on an escort MK2 and fitting an oil cooler made all the difference.
Mac
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clbarclay
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| posted on 23/4/05 at 08:18 PM |
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I dought its the reason for running quite so hot, but does the cooling system have anti freeze in it?
Good anti freeze prevents freezing in winter and improves engine cooling when running.
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Jago Swizz
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| posted on 23/4/05 at 08:31 PM |
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Theres no antifreeze in it at the moment - just water, as i've drained it off a coupla times trying to find the fault.
As mentioned, the water pump is new - its a proper pattern replacment with cast impeller. There is flow around the system as the bottom hose gets nice
& hot too
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Jago Swizz
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| posted on 23/4/05 at 08:37 PM |
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I haven't considered an oil cooler - as its probably better positioned for cooling than in the donor escort - its in a Jago Geep. Theres plenty
of space in the engine bay.
Its going to stoneleigh hot or not - suppose it'll keep the speed down.
I haven't checked the gauge or sender now you mention it. However, the electric fan pickup is in the top hose & I haven't fiddled with
the potentiometer. As said, the fan is always ready to kick in. This is why I think its running kinda hot.
I half wish i'd junked the engine at the first sign of trouble considering the money spent so far, but thats all hindsight I suppose.
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gazza285
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| posted on 23/4/05 at 08:41 PM |
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How evenly is the radiator heating up? Cool spots indicate a knackered rad.
You might also want to look at the amount of air getting to it, as the bottom hose should be quite a bit cooler than the top hose. If its not the
airflow at fault then get a bigger rad.
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Jago Swizz
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| posted on 23/4/05 at 08:46 PM |
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Okay - i've not hit the red wine yet so i'll tek it to the M60 & back & check the rad - then i'll pull my hair out.
Swizz...
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David Jenkins
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| posted on 23/4/05 at 09:08 PM |
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I have found to my anguish that the X-flow is really bad for holding onto airlocks - it took a couple of refills to get the system totally clear and
working properly.
Might be worth a bit of investigation...
rgds,
David
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Jago Swizz
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| posted on 23/4/05 at 10:31 PM |
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Ok, its been from Mottram to Denton & back several times at 60mph, and finally home to Hyde.
The gauge got just over 3 quarters high.
On returning home I checked the rad - all even.
The heater has been removed so there is just a link pipe from the manifold to the water pump. This wasn't particularly hot so a possible airlock
in the head.
Something else noticed. Due to the positioning of the rad, the top hose is unavoidably 'kinked' at the u bend. This will be causing some
restriction to the flow but as the rad' is hot, coolant is getting through so cannot be the source of the problem surely?
To rule out the head gasket theory I removed the plugs - all were a slight rusty colour and basically very clean so i'd say there wasn't
much amiss there. Might be worth rechecking the timing though.
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owelly
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| posted on 23/4/05 at 10:58 PM |
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As previosly mentioned, borrow/hire an Infra-red temp gun. You just piont a red spot at whatever and it tells you how hot it is. Then check top,
bottom, middle of rad to check flow. Check various areas of the head for cooler/hotter bits. Check the hoses to see if there is flow through them and
finally point it at some poor drunk on the way back from the pub so he thinks he's been targetted by a sniper......
http://www.ppcmag.co.uk
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lexi
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| posted on 24/4/05 at 08:45 AM |
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Hoses could be compressing at high speed causing coolant flow restriction. Happens on my big Nissan. If it were so trick is to put a steel tube at
bend inside hose. Only a long shot but you never know.
Lexi
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britishtrident
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| posted on 24/4/05 at 09:49 AM |
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Most likely ignition is too retarded or advance centrafugal mechanism is kyboshed or the vac advance capsule as become detahed from the link to the
base plate..
If you have points check they haven't closed up with Ford Fomoc/Autolite distributers the points tend to close up in the firsty few miles use
corect gap for new Fomoco points is 0.027" -- in service the gap tolerance band is 0.023" to 0.027"
[Edited on 24/4/05 by britishtrident]
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viatron
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| posted on 24/4/05 at 10:02 AM |
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You also said it was in a jago, is the airflow to the rad ducted? if it s not you could find that the air is passing down the side of the rad instead
on through, path of leat resistance etc. A kink in any cooling pipe cannot be good and must affect flow in some way.
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Jago Swizz
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| posted on 23/6/05 at 01:16 PM |
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Lets just say it developed!
I ran several long journeys fairly hot. Eventually last month the bottom hose blew on the motorway & REALLY overheated. Replaced the hose &
tested to find blown headgasket.
As it was stripped down I had the valve seats replaced & face skimmed and reassembled.
So whats it like? Yep, still runs hot!
I'm clutching at straws now but am considering replacing the rad. If I leave the elec fan on it maintains 3/4 temperature at tickover.
As i suspect the cam is non standard i'm considering uprating the rad. I don't want any hassles fitting an expansion tank but have seen
the early micra rad on here - i'm running a 1.6 xflow - anyone any ideas?
I'm also considering throwing it back at the rollong road guys as i'm sure its running too lean.
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NS Dev
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| posted on 23/6/05 at 01:28 PM |
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He he!!
Had all this when I built my 16v manta years ago.....................was TOLD I needed a bigger rad...............was TOLD all sorts of
things........then my mate said "has it ever blown the pressure cap"..........no says I!
Well, it's not getting THAT hot then is it!!
Put a thermocouple and thermocouple reader into the top hose and measured the ACTUAL water temp and.............it was fine. I just shunted the gauge
with a resistor so that hot on the gauge was actually hot!!
Check the gauge first, they very often lie!
Incidentally, I ran mine with the (manually switched) rad fan on nearly all the time, which kept it at 3/4 of the gauge, but this was actually
overcooling it when I checked with the thermo!!
[Edited on 23/6/05 by NS Dev]
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Jago Swizz
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| posted on 23/6/05 at 02:04 PM |
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Yeah, we pointed an infared thermo to the head & got95 degrees. Also the bottom hose is equally hot whic makes me think the rad.
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rusty nuts
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| posted on 23/6/05 at 07:03 PM |
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If you take your rad to a radiator specialist they should be able to tell you if its blocked ,the fact that the bottom hose is as hot as the top hose
makes me suspect it may not be the rad. If all else fails one way that will reduce the overall temperature by at least 15deg is to use a bottle of
Water Wetter.
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Marsdalebear
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| posted on 24/6/05 at 08:04 AM |
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Junk the rad and fit a Polo rad,problem solved.
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Jago Swizz
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| posted on 15/7/05 at 04:18 PM |
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Conclusion.
Last thing to try? Took the Rad' to a local rad repair shop- Dixons in Denton.
He replaced the core with a thicker one - simple as that. Refitted and test driven to destruction it sat half way on the gauge all the way.
Thank gawd for that!
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NS Dev
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| posted on 15/7/05 at 04:25 PM |
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glad to hear that you got it sorted!
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