smac
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| posted on 5/5/06 at 08:01 PM |
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Pinto overheating (I know!)
I know this subject is a frequent visitor to this forum and I promise Ive searched and read all the other threads but to no avail.. so here goes
2.00 pinto , hot cam , unknown headworks, twin 45s. polo rad. Thermo housing to top of rad, bottom of rad to water pump big hose, water pump small
hose to manifold via t to header tank bottom hose, header tank top to thermo housing bleed.
After idling for 10 minutes the temp gauge is right at the top. The rad is cold to start with then the thermo opens and it gets hot. If I switch on
the fan it seems to make a marked difference to the temp of the rad but this is not reflected on the temp gauge. Timing is at 12 btdc and the carbs
have not been setup so maybe too lean/rich (but would it make that much difference?)
I have replaced the stat, the water pump and all the hoses and tried filling/bleeding numerous ways but still the problem persists
Any other suggestions before I see if my lump hammer will fix it?
thanks for looking
Simon
PS anyone at Elvington tommorow? Ill be there in my brothers VXR220 so say hello.
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mookaloid
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| posted on 5/5/06 at 08:07 PM |
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does it actually over heat/ chuck water out etc?
or is your gauge accurate?
just a thought....
Mark
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ned
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| posted on 5/5/06 at 08:09 PM |
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also where is the water temp sensor fitted? i'm no expert on pinto's but is it possible there is an air pocket somewhere in the engine or
near to where the water temp sensor is?
Ned.
beware, I've got yellow skin
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Andy S
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| posted on 5/5/06 at 08:25 PM |
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Is it really overheating - spitting out water all over the place lifting the rad cap etc. or is it just overheating becasue the gauge tells you its
too hot?
If it is genuinely overheating you then check the rad for any cold spots and make sure that you are getting good flow from the pump.
Make sure that the cooling fan is rotating in the right direction for the blades and that its also mounted correctly - sucking /blowing.
The header tank should connect to the botton of the rad i.e suction side not the pressure side.
Otherwise get a decent digital thermometer and measure the actual temp - At 120oC Gauge actual is 78 on my car! sensor mismatch.
Cheers
Andrew
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oliwb
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| posted on 5/5/06 at 08:32 PM |
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One of a few things:
Air in the system,
Faulty rad pressure cap,
Running to lean
Solve them all then come back.....Might be worth consdering an oil cooler if you can possibly fit one....helps alot. Oli.
If your not living life on the edge you're taking up too much room!
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DarrenW
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| posted on 5/5/06 at 09:20 PM |
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Im having a strange experience as well. By no means solved but ill share data.
Mine is 2.0 pinto, ported injection head, 285 cam. Also have 12deg at idle. 38DGAS carb.
Micrs rad, no header tank. It used to keep blowing water out. Block was sludged and im convinced it was air locked. I flushed for ages with hosepipe.
Re-filled and now better (doesnt blow out as much). Still brown water present (diluted this time) so ill chuck in some Forte flush.
Fan comes on at 98deg, off at 94deg. Micra mk1 rad. In sunny weather carb gets too hot and car cuts out. im convinced i need lower temp rad stat -
watch this space for help!!!
Im going to fit fan bypass switch and exhaust wrap next. already cut some bonnet vents.
Some cars run lovely - others are plauged with 1960's overheating issues. Havent sussed it yet but working hard to resolve.
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Anglia66
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| posted on 5/5/06 at 09:26 PM |
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SMAC,
I had the same problem when I fitted a crossflow into my Anglia and it was because the temp sender wasn't right for the temp gauge so it always
read hot.
Once I fitted the correct sender all was well.Might be worth a look.
[Edited on 5/5/06 by Anglia66]
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smac
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| posted on 5/5/06 at 10:51 PM |
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Some interesting stuff there.
I think it is properly over heating as it will boil out of the header tank with the cap off.
The rad is hot all over and the fan is the right way. Is the header connection to the lower rad hose a must? Im sure Ive seen setups with the feed
to the redundant heater circuit but I can change this.
I had discounted the gauge because you could watch it heat up ie it didnt go straight to hot and stay there, but i have a spare set of gauges
somewhere so ill try them. The same sort of applies to the sender. I also thought that even if they were the wrong ones they would still register
the temp difference with the fan on - but ill get a new sender just in case.
Ill try rich out the carbs but I darent have it on a rolling road until the temp is more managable.
Ive flushed the block with water from a hose pipe and it wasnt sludgey but the water does come out brown.
So ill try it all out and report back.
Thanks for your help
Simon
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Dusty
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| posted on 5/5/06 at 11:04 PM |
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Pinto's like to run around 90. 98 is too hot so try lower rated thermostat. Is the thermostat fitted the correct way round, body to the head
not in the top hose.
Flow in Tstat bypass is from manifold to pump. Can it do this.
Sounds like it could be an air lock. Best way I have found to bleed is run it with the rad cap off, let it blow water and air out and stand there with
a watering can constantly refilling the rad till it settles.
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NS Dev
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| posted on 6/5/06 at 12:20 AM |
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They will always blow coolant out with the cap off!!!!!
You almost certainly have the wrong sender for your gauge, unless a pinto has thrown all its water of has a stuck shut thermostat it wont overheat.
quote:
Originally posted by smac
Some interesting stuff there.
I think it is properly over heating as it will boil out of the header tank with the cap off.
The rad is hot all over and the fan is the right way. Is the header connection to the lower rad hose a must? Im sure Ive seen setups with the feed
to the redundant heater circuit but I can change this.
I had discounted the gauge because you could watch it heat up ie it didnt go straight to hot and stay there, but i have a spare set of gauges
somewhere so ill try them. The same sort of applies to the sender. I also thought that even if they were the wrong ones they would still register
the temp difference with the fan on - but ill get a new sender just in case.
Ill try rich out the carbs but I darent have it on a rolling road until the temp is more managable.
Ive flushed the block with water from a hose pipe and it wasnt sludgey but the water does come out brown.
So ill try it all out and report back.
Thanks for your help
Simon
Retro RWD is the way forward...........automotive fabrication, car restoration, sheetmetal work, engine conversion
retro car restoration and tuning
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Peteff
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| posted on 6/5/06 at 08:36 AM |
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Take the thin hose off at the stat while you fill it up. Is the Polo rad the one with no filler neck?
yours, Pete
I went into the RSPCA office the other day. It was so small you could hardly swing a cat in there.
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Andy S
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| posted on 6/5/06 at 08:47 AM |
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The header/expansion tank must feed the pump inlet.
Withe the cap off there should be no other effect other than the water level rising slowly as the car heats up.
I would remove the stat and if there is not one fitted drill a 4mm bypass hole in it so that there is always a small amount of flow to the rad - this
does two things - it slowly warms the rad so that when the stat does open it does not temp shock the whole system and it also help prevent air locks
behind the stat. - Make sure that the hole is at the top.
Cheers
Andrew
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rusty nuts
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| posted on 6/5/06 at 08:56 AM |
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Some but not all pinto's used to have a thermostat housing with a small blanking cap or hose that went to the top of the header tank. If you
have one of those with the blanking cap try removing the cap when you fill the cooling system . May be worth fitting a bleed valve using a short hose
and an old tyre valve with the rubber and the valve core removed just fit a tyre type valve cap ,or if you can, run a pipe from the outlet to the top
of the header . This will bleed the system easier . Air locks may not be your present problem but using a bleed will eliminate them
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britishtrident
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| posted on 6/5/06 at 11:32 AM |
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As others have said Really sounds much more like a mismatch between the sensor and guage -- one of the reasons I used an old fashioned expansion bulb
capilary type guage.
Digital temperature probe thermometers are so cheap from Maplin theses days it is worth buying one just for a sanity check.
Expect a tempersture at the thermostast outlet of somewhere between 88 and 99c with the engine fully warmed up. The coolant should only boil over
110c with pressure cap on.
[Edited on 6/5/06 by britishtrident]
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smac
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| posted on 8/5/06 at 07:15 PM |
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Cured!
And its a gold star to all those who suggested a dodgy sender unit. New one in today and needle now sits in the middle of the gauge although......
the engine does actually seem to run colder ( this is probably my imagination) so it could also have been an air lock behind the sender which was
released when I took it out. Either way jobs a goodun.
Thanks
Simon
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