Where to start if your CF is misbehaving and you're not sure where the problem may be.
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Frothy coolant

Post by Mikey2301 » Wed Feb 14, 2018 2:42 pm
Joined: Fri Feb 09, 2018 2:14 pm
Posts: 5
Hi all, firstly thanks for the add and all the information collected here it's been very helpful, my names Mikey I'm from Dorset and am the proud owner of a 1984 cf ambulance (wadham stringer body) with a 2.3 slant 4 engine.
I picked her up a couple of months ago, she's not seen a whole lot of use in her life with only 33000 genuine miles on the clock, and she's been off the road for the past few years.
I've got her running reasonably smoothly after working my way through a host of electrical problems, but apon flushing out what was left of the old coolant and refilling I've found a new problem, i started her up with the radiator cap off hoping to burp out any remaining air, and im getting a thick bubbly froth appear,I have no mayo in the oil which is fresh and clean, and the froth isn't oily at all. Im hoping it isn't the head gasket which seems unlikely to me being such low mileage and running so well, but I can't figure out where all this air is coming from, heater hoses are getting warm. Any help much appreciated as I'm stuck
Many thanks

Re: Frothy coolant

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Post by VDUB384 » Club admin » Wed Feb 14, 2018 2:53 pm
Joined: Wed Sep 12, 2012 9:01 am
Posts: 1279
If both your heater hoses are getting hot this means the water is circulating ok, usually you have to bleed the air out through the heater hose but if like you say they're both hot then seems like the air is out as to the froth your talking about could it be something you flushed it out with.Only thing to rule out cylenders head gasket is to do a compression test on it.
Dave
Whilst good maintainece is the best prevention"If its not broken don't fix it."
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Re: Frothy coolant

Post by Mikey2301 » Wed Feb 14, 2018 3:18 pm
Joined: Fri Feb 09, 2018 2:14 pm
Posts: 5
I only flushed it through with water, will compression test as soon as my neighbors in to lend me his tester, just hoping it could be an air lock somewhere or something, I recall reading something about a bleed screw for the cooling system? I don't know where this is or if this could be the issue? Also my temperature gauge isn't working so I have no idea if it's overheating and so have only been running it for very short periods, I tried earthing the sender wire and guage does nothing, could you tell me where the voltage stabiliser is located so I can test that as my fuel gauge is a bit on and off too
Thanks for your help

Re: Frothy coolant

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Post by Phil Bradshaw » Club admin » Wed Feb 14, 2018 5:35 pm
Joined: Sun Sep 02, 2012 7:15 pm
Posts: 3373
If a cylinder compression test doesn't indicate a head gasket blow and what's in the radiator doesn't smell of exhaust gases then try a proprietary cooling system/radiator flush, e.g. Wynns, which should clear out stuck on crud like old additives and corrosion scale which may be reacting with what's in your water supply. Follow the destructions for the flush reagent used - some have to be drained off in a short time to prevent damage to soldered joints in the radiator.

Voltage regulator is behind the instruments panel -

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To release the speedometer cable from the speedometer press the tongue of the retaining clip down against the back of the speedometer -

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Test for regulator -

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Analogue meter is best. Once the unit has warmed up the meter pointer should swing between battery voltage and about 8V to average at around 10V mid-swing. Anything else (e.g. steady battery volts, 0V, 8V) indicates faulty regulator.

LM7810 linear regulator can be used to replace burned out hot wire innards -

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Exchange units with LM7810 regulator fitted available from the club Parts Department - ask at the Front counter.

Howto for DiY conversion is in the Reference Library in the Subscribing Members area.
  • What is real is not the external form but the idea, the essence of things. Constantin Brâncuși

Re: Frothy coolant

Post by Mikey2301 » Wed Feb 14, 2018 6:06 pm
Joined: Fri Feb 09, 2018 2:14 pm
Posts: 5
Thats absolutely spot on cheers for the info guys, will update once I've done a compression test, the froth doesn't smell like exhaust fumes it kind of smells like antifreeze even though I only filled it with water for the moment, the froth also seems to dissipate over night even with the cap on and doesn't seem to blow out if I run it with the cap on, some sort of reaction seems logical it seems like a lot of air would need to be getting it to cause the amount of froth there is, no big bubbles, just a seemingly endless stream of froth, and I can't understand how it's not blowing out with the cap on lol

Re: Frothy coolant

Post by Mikey2301 » Thu Feb 15, 2018 2:23 pm
Joined: Fri Feb 09, 2018 2:14 pm
Posts: 5
I've just done a compression test revealing a very even 115psi per cylinder so thankfully it appears it's not the head gasket

Re: Frothy coolant

Post by Mikey2301 » Thu Feb 15, 2018 7:05 pm
Joined: Fri Feb 09, 2018 2:14 pm
Posts: 5
Okay so I've got the gauges working (was just a loose connection to the stabilizer) ran it up and it's not overheating, but I've discovered a coolant leak that I suspect may be the source of the air getting in, I can't actually see exactly where it's dripping from but somewhere around the water pump, dripping off the bottom of the cam cover the bit of the loom below it, I've got a little bit of play in the pump shaft also, so i think it's water pump and timing belt time. can anyone point me in the right direction to find the correct pump? Will the water pumps for the diesels or Opel cih engine fit? Seems there's lots of these available
Many thanks once again

Re: Frothy coolant

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Post by Phil Bradshaw » Club admin » Fri Feb 16, 2018 9:39 am
Joined: Sun Sep 02, 2012 7:15 pm
Posts: 3373
Coolant dripping from the bottom of the cam belt cover usually is the water pump leaking. Quinton Hazell QCP590 pump for fixed fan, QCP2698 for viscous coupling fan. Service exchange water pumps available from the club Parts Department.

Cam belt only needs renewing when the teeth are worn (gaps at pulley teeth) or cracks are evident at teeth roots. Usually available as Gates 5023, Quinton Hazell QTB120.
  • What is real is not the external form but the idea, the essence of things. Constantin Brâncuși

Re: Frothy coolant

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Post by VDUB384 » Club admin » Fri Feb 16, 2018 10:08 am
Joined: Wed Sep 12, 2012 9:01 am
Posts: 1279
Hi Mikel I strongly advise you to use the club for any spares as Phil reconditions anything that can be reconditioned they most likely will be cheaper than elsewhere and you know your getting a quality unit.
Dave
Whilst good maintainece is the best prevention"If its not broken don't fix it."
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