#1: Cant figure his out!!! Coolant pressure and temp!!!! Author: Jiten, Location: LeicesterPosted: Thu Jan 26, 2012 6:19 pm ---- Evening folks,
So this is my problem...
Found my passenger footwell soaking a week ago, and sure enough it was between the joint where the pipes met the heater matrix just after the firewall...
So i drained all the coolant from the bottom radiator hose and opened the bleed valves and the cap on the expansion tank. Changed the o-rings on the heater matrix and put everything back together...
Filled new coolant following the procedure on here, closed off the heater matrix bleed valve first and then the thermostat bleed valve, started the engine and ran at approx 1500 rpm. I noticed instant steam coming from the expansion tank and approx 30-50secs later the coolant reached the top of the expansion tank and started to overflow!!! temp on the guage was approx at 75.
Dropped back down to idle and more steam was coming out the expansion tank! Got quite worried so thought i'd leave it overnight, left expansion tank open, came back to it this morning checked coolant level, topped up with coolant to max mark, put new cap on expansion tank and went for a drive.
10 mins of driving sensibly i thought id stop over and check everything was ok under the hood, temp was showing just under 80. I checked the hoses and they were solid, like rock hard solid! Couldnt see any leaks...
Another 10mins of driving but giving it a blast at 2-3000 rpm, i get home and all i can see is steam creeping out the bonnet the temp has never reached 90, infact 80-82 max!
Open the hood to find there's coolant all over the engine bay all from the expansion tank!!!
So my question is.... What the hell is going on????
If it helps once i switch off the car you can hear a fairly prominent hiss from the expansion tank cap and if i open the thermostat bleed valve i get air coming out for approx 5secs before coolant starts seeping out!
Initial indication would assume it needs bleeding but i've followed the guide on here like 3-4 times n bled it, so i really dont know why its doing this now! Never been a problem before the leak and change of coolant!
Car is a 2001 2.0 HDI
Appreciate any help guys,
Thanks a million!
#2: Re: Cant figure his out!!! Coolant pressure and temp!!!! Author: cartoonhead, Location: North ManchesterPosted: Thu Jan 26, 2012 7:34 pm ---- sounds like back pressure , start at the basics then work your way up.
check if thermostat is working , remove thermo and put in a pan of boiling water and see if it opens
check the water pump is working , while thermo is out and its cover is off start car for a second or two and see if the remaining water is being pumped out
if both of them are ok , get the engine compression tested
( could be head gasket )
if it's the water pump thats failed while doing the water pump get new timing belt , tensioner and roller as a kit
#3: Re: Cant figure his out!!! Coolant pressure and temp!!!! Author: Seabook, Posted: Thu Jan 26, 2012 7:37 pm ---- is the radiator pipe warm then?
#4: Re: Cant figure his out!!! Coolant pressure and temp!!!! Author: E5GDM, Location: EssexPosted: Fri Jan 27, 2012 12:37 am ---- Perhaps the expansion tank top needs replacing.
#5: Re: Cant figure his out!!! Coolant pressure and temp!!!! Author: Jiten, Location: LeicesterPosted: Fri Jan 27, 2012 1:29 am ----
cartoonhead wrote:
sounds like back pressure , start at the basics then work your way up.
check if thermostat is working , remove thermo and put in a pan of boiling water and see if it opens
check the water pump is working , while thermo is out and its cover is off start car for a second or two and see if the remaining water is being pumped out
if both of them are ok , get the engine compression tested
( could be head gasket )
if it's the water pump thats failed while doing the water pump get new timing belt , tensioner and roller as a kit
Thermostat is defo working, changed it for a genuine pug one from dealer when i flushed the system, could try the water pump test, will let ya know how i get on, thanks
#6: Re: Cant figure his out!!! Coolant pressure and temp!!!! Author: Jiten, Location: LeicesterPosted: Fri Jan 27, 2012 1:30 am ----
Seabook wrote:
is the radiator pipe warm then?
Yes, bottom pipe gets warm pretty quickly and the top one gets warm after 10-15mins, temp guage never goes above 80 though
#7: Re: Cant figure his out!!! Coolant pressure and temp!!!! Author: Jiten, Location: LeicesterPosted: Fri Jan 27, 2012 1:31 am ----
E5GDM wrote:
Perhaps the expansion tank top needs replacing.
Replaced this yesterday for new genuine part from pug dealer!
#8: Re: Cant figure his out!!! Coolant pressure and temp!!!! Author: Jiten, Location: LeicesterPosted: Fri Jan 27, 2012 1:33 am ---- Gonna take the car too work (approx 20min journey) carry a 5ltr tub of coolant and see what happens! Wish me luck lol!
#9: Re: Cant figure his out!!! Coolant pressure and temp!!!! Author: Timon2210, Location: PalestinePosted: Fri Jan 27, 2012 2:24 am ---- I think you got a clogged radiator,which makes the coolant cycle not work the way it should,therefor it creat a pressure in the system,and the weakest point is expansion tank,that is why the coolant comes out,try to flush the radiator,and make sure water runs smoothly.
About the top hose of the radiator it shouldn't get HOT unless the thermostat open so that the coolant from the engine go to the radiator to cool down,and get back to the engine.
#10: Re: Cant figure his out!!! Coolant pressure and temp!!!! Author: Jiten, Location: LeicesterPosted: Fri Jan 27, 2012 10:14 am ---- journey into work this morning was ok, temp did not go above 75, but was driving at no more than 2500rpm.
part of me does not want to admit its the head gasket! but could be looking that way!
#11: Re: Cant figure his out!!! Coolant pressure and temp!!!! Author: Jiten, Location: LeicesterPosted: Sun Jan 29, 2012 7:22 am ---- Water pump works, but after a fairly long drive ive noticed coolant still overflowing from the expansion tank, and can hear a hiss of air from the expansion tank cap, if i unscrew the wheel cap bleed valve on the theromstat housing it relieves the pressure in the system, first air and then the coolant starts seeping out.
Any ideas folks as im bamboozled!!!
Thanks
jiten
#12: Re: Cant figure his out!!! Coolant pressure and temp!!!! Author: parkesie, Location: HampshirePosted: Sun Jan 29, 2012 9:08 am ---- air lock in the system try re bleeding do you get hot air through the blowers?
sounding alot like a head gasket job tho.
How quickly do the pipes become pressurised solid?
#13: Re: Cant figure his out!!! Coolant pressure and temp!!!! Author: Jiten, Location: LeicesterPosted: Sun Jan 29, 2012 9:32 am ----
parkesie wrote:
air lock in the system try re bleeding do you get hot air through the blowers?
sounding alot like a head gasket job tho.
How quickly do the pipes become pressurised solid?
Tried bleeding it like 10 times!!! Pipes become pressurised as soon as i start the engine!
Noticed a constant leak just below the alternator pulley, pretty sure its coming from the water pump!
Is it worth getting the head done at the same time as the water pump and cambelt?
Do you guys have any idea of an approx cost?
Thanks
#14: Re: Cant figure his out!!! Coolant pressure and temp!!!! Author: parkesie, Location: HampshirePosted: Sun Jan 29, 2012 9:48 am ---- Instant pressurisation screams head gasket or crack in cylinder lining or head either ways heads got to come off to see .
get belts and coolant pump done at the same time.could just be the overpressure causing the pump to leak but not worth chancing it for the cost of replacing it.
#15: Re: Cant figure his out!!! Coolant pressure and temp!!!! Author: Jiten, Location: LeicesterPosted: Sun Jan 29, 2012 9:55 am ---- What a $hitta!!! These dumbass french cars are more trouble then they're worth! Spent £400 on the damn thing in the last 1.5 months! Its a money pit!!!
#16: Re: Cant figure his out!!! Coolant pressure and temp!!!! Author: Deckchair5, Location: Bath UKPosted: Sun Jan 29, 2012 2:03 pm ---- Your pipes becoming as hard as a rock as soon as the engine is started and an overpressurised system sounds like there is no flow through the heater matrix and your pump is working hard against a dead stop
Initially, with engine cold, coolant flows from bottom of radiator, through the pump, through the engine then through the heater and back to the engine block. If there is a blockage then the pipes go brick hard, water pump strains against the dead stop and blows seals and the system overheats on that side
What I would try is to backflush the heater matrix to see if there is any restriction there. If you disconnect one of the heater hoses where it attaches to the engine and then connect a garden hose to that pipe ( twist sprinkler nozzle usually fits nicely in there) and then gently turn the tap on. Water should circulate all around the engine and gush out where you disconnected the pipe. If is doesn't then you have a blockage. It's a cracking way to get rid of air locks in the heater matrix too
It wont be the first time someone has put a therrmostat in the wrong way around too - worth a check when you have the system drained again
#17: Re: Cant figure his out!!! Coolant pressure and temp!!!! Author: millerman, Location: KentPosted: Sun Jan 29, 2012 2:17 pm ----
Timon2210 wrote:
I think you got a clogged radiator,which makes the coolant cycle not work the way it should,therefor it creat a pressure in the system,and the weakest point is expansion tank,that is why the coolant comes out,try to flush the radiator,and make sure water runs smoothly.
About the top hose of the radiator it shouldn't get HOT unless the thermostat open so that the coolant from the engine go to the radiator to cool down,and get back to the engine.
My Wifes car had coolant being expelled from the expansion bottle untill i found the bottom of the rad completely blocked, ie; bottom hose was cold all the time, gotta new rad to go in next few days.
#18: Re: Cant figure his out!!! Coolant pressure and temp!!!! Author: Deckchair5, Location: Bath UKPosted: Sun Jan 29, 2012 2:33 pm ---- Certainly sounds like a blockage doesn't it. Thing is that the radiator doesn't come into the circuit until the thermostat opens, it's a secondary parallel circuit. You could clamp the radiator hose shut and the engine wouldn't be bothered - until the thermostat opened - and then it would overheat very quickly. The fact Jiten is experiencing rock hard and over pressurised pipes straightaway points to a blockage or air lock in the primary system
#19: Re: Cant figure his out!!! Coolant pressure and temp!!!! Author: Pan24v, Location: SoutheastPosted: Tue Jan 31, 2012 2:08 pm ---- Sorry to say this but I'm pretty certain its the head gasket!
I've just bought a 2.0 HDi that had the same problem, it was basically blowing the cooling system as quick as you could blow a tyre up on an airline!
Turns out once stripped down that it was letting by in 2 water ways on pot 2 and looked seriously dodgy in other areas.
I also found that my coolant temp wasn't consistent, a bit up and down?
Also if you rev the engine you can hear water swirling inside the cabin?
Stick your nose over the coolant tank with the engine running ( better when cold due to the risk of coolant bubbling over) and you should smell exhaust gases or an oily type of smell, also check the tank for emulsifying.
Sorry if it is bad news, those are a few symtoms i diagnosed before i decided to take the car on.
Good luck mate.
#20: Re: Cant figure his out!!! Coolant pressure and temp!!!! Author: Jiten, Location: LeicesterPosted: Wed Feb 01, 2012 2:24 pm ---- Hi guys,
So gave it in at a garage, the water pump was leaking like a bit@h!!! Looks like instant pressure in the system mustve blown the seals! Also i have done as Pan24v suggested and can smell the exhaust fumes and the emulsifying in the tank
May aswell get the HG done with a new cambelt and waterpump! There goes feb's salary and commission!
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temp on the guage was approx at 75.
the temp has never reached 90, infact 80-82 max!
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