Birty Dastards Jeep Club

Tech Forum => Workshop => Topic started by: onoil on May 02, 2010, 07:26:38 PM

Title: 2.5td xj bleeding cooling system
Post by: onoil on May 02, 2010, 07:26:38 PM
evening!
I just fitted a new radiator to a mk2 2.5td but cant seem to get rid of the air, huge bubbles and no heater despite running it with header tank cap off and heater on for some time. is the tap on top left of radiator for bleeding the system, a pipe runs from there to back to the header tank?
thanks
Title: Re: 2.5td xj bleeding cooling system
Post by: Bubba on May 02, 2010, 08:29:08 PM
i do hope the head aint stuffed may i ask why you needed a new rad
Title: Re: 2.5td xj bleeding cooling system
Post by: onoil on May 02, 2010, 08:45:43 PM
old one was leaking
Title: Re: 2.5td xj bleeding cooling system
Post by: Dave69 on May 02, 2010, 09:30:30 PM
fill the system with the radiator cap off and leave the engine running. put the heater on if you need the heat. the engine will slowly warm up. keep adding coolant to the system. When the engine is at temperature the thermostat will open causing the radiator coolant level to drop. Add more coolant until it is level with the top of the rad. Slowly squeezing the top rad hose and the one to the water pump will push any trapped air through the system. Once the coolant is too warm to touch put the radiator cap back on then add some coolant to the header bottleso that the level is half way between the markers. At this point you should be getting some warm air from the heater.
Title: Re: 2.5td xj bleeding cooling system
Post by: Mike Pavelin on May 02, 2010, 10:09:07 PM
Yes, it is an air bled screw on the radiator.
Title: Re: 2.5td xj bleeding cooling system
Post by: onoil on May 03, 2010, 09:22:23 AM
Ok thanks, so I assume the bleed valve is open when positioned in line with the outlet and directs any air back to the header tank & closed once bled?
assuming I can turn it without snapping it off as its solid!
Title: Re: 2.5td xj bleeding cooling system
Post by: Mike Pavelin on May 03, 2010, 10:19:06 AM
No you unscrew it and let theair leak out.
Title: Re: 2.5td xj bleeding cooling system
Post by: onoil on May 03, 2010, 05:25:12 PM
I see, thanks
checked the thermostat first and it doesnt appear to be opening so I will replace before going any further.
Title: Re: 2.5td xj bleeding cooling system
Post by: The Smiths on May 03, 2010, 10:50:32 PM
most of the time there is no need to use that - infact I never have :icon_rolleyes:

keep topping up and air normaly comes out.

sqeeze top hose a bit to squirt more air out.

start up and top up again


Not by the book - but works
Title: Re: 2.5td xj bleeding cooling system
Post by: onoil on May 04, 2010, 04:53:34 PM
yes thats what I normally do, & it normally works!
the air bleeder only opens about 90deg as did the one on the old rad and doesnt seem to do much, have now replaced the thermostat as it definately wasnt working.
Re filled and still lots of big bubbles! also tried bleeding from the heater hose, the heater is now about as warm as its ever been. I guess I will run it as is and see what happens, its isnt overheating although the gauge occasionally goes up to about 105 and then drops quickly to about 85 which it usually runs at when fully warmed up on tickover??
Title: Re: 2.5td xj bleeding cooling system
Post by: Dave69 on May 04, 2010, 07:50:21 PM
only had warm air blowing out of the diesel and no where near the same heat as i get from the petrol.
Title: Re: 2.5td xj bleeding cooling system
Post by: onoil on May 05, 2010, 12:47:51 PM
hmm, looks like it may be the hg as I feared, took it on a run and it boiled, ok on the way back though strangely.
I have also done a basic test with a block tester on the header tank and it tells me there are gasses in the water, which would explain the neverending supply bubbles!
Is that a good enough confirmation??  I want to be sure before before I right it off!
Title: Re: 2.5td xj bleeding cooling system
Post by: onoil on May 05, 2010, 06:11:23 PM
just did another 60 miles and its ok until 70mph it exceeded for a short time, need to rule out water pump I think.
 Would the outlet pipe be the small one that goes to the rear of thermostat housing? I have a manual on cd but me disk drive is buggered!
Title: Re: 2.5td xj bleeding cooling system
Post by: The Smiths on May 05, 2010, 07:14:55 PM
remove the water way that links the heads - start it up and see if any bubbles are coming from any heads - you will also see which one(s) have gone :icon_winkle:
Title: Re: 2.5td xj bleeding cooling system
Post by: Mike Pavelin on May 05, 2010, 07:38:48 PM
Sounds like cracked head disease for sure.
Title: Re: 2.5td xj bleeding cooling system
Post by: Bubba on May 05, 2010, 08:34:08 PM
damn my kneejerk
Title: Re: 2.5td xj bleeding cooling system
Post by: onoil on May 05, 2010, 09:08:31 PM
thanks chaps, took water way off, good tip, one head appears to be blowing bubbles!
whats the likely to cost to get them all pressure tested once removed?
Title: Re: 2.5td xj bleeding cooling system
Post by: tree man on May 05, 2010, 09:38:30 PM
My condolences.  Many such Jeeps have been scrapped as the cost of repairs (done by a garage) can be high in relation to the value of the vehicle. If you can do the spanner work yourself then it's a head skim, replacement head(s) and gaskets. If your lucky they will feel sorry for you and only charge you for testing and skimming x2 heads instead of x4.
I don't think that the engine is in this respect is any worse than say a Tdi Land Rover as it's very common for them to go at around 100k but it's just one horrible, horrible, knuckle scrapping, spanner throwing, how the f**k do I get that off type of job. I did mine 40k ago and no further problems, however it took about 2mths for my blood pressure to get back down and retrieve the spanners.
Title: Re: 2.5td xj bleeding cooling system
Post by: Dave69 on May 05, 2010, 09:54:15 PM
individual heads so it's a case of scrapping the head that's blowing bubbles. never needed to skim any of the heads when i owned one even after serious overheating.

dump a bottle of "K Seal" in and see what happens. this is classed as a temporary fix until you decide what to do. surprisingly it does create a temporary fix
Title: Re: 2.5td xj bleeding cooling system
Post by: The Smiths on May 05, 2010, 11:14:08 PM
agree with K seal.

and you do not skim the heads - if needed a light clean up of the surface yourself - they are not big enough to distort for skimming

If you are going to do it yourself remove all heads, manifolds and turbo in one (undo head bolts and exhaust down pipe, turbo oil feed etc and get help to work the lot out of the engine bay)  - then work on them when you can get to the bolts :icon_winkle:
Title: Re: 2.5td xj bleeding cooling system
Post by: onoil on May 05, 2010, 11:47:17 PM
thanks
not yet sure weather to spend any more time/money on it, it had a new hg only a few months ago after I bought it as the heads had to be removed for core plug replacement, not by myself.
I should have had them pressure tested at the time although the culprit here was obviously the stuck thermostat.
Title: Re: 2.5td xj bleeding cooling system
Post by: Dave69 on May 06, 2010, 08:19:05 AM
The K seal will help alot and allow you time to work out what to do, might be worth considering a petrol cherokee.
Title: Re: 2.5td xj bleeding cooling system
Post by: Bubba on May 06, 2010, 06:45:14 PM
for the cost k seal is your very best shot of a cure while you think about what you want to do or if you have low morrals you could just use that and sell it sharpish


not my recomendation but i aint you and you must please your self and your pocket
Title: Re: 2.5td xj bleeding cooling system
Post by: onoil on May 10, 2010, 09:05:20 PM
we have now parted, simply couldnt afford to spend any more money or for it to be off the road any longer.
I will probably be back, at some point!
cheers
Title: Re: 2.5td xj bleeding cooling system
Post by: wildrover on May 16, 2010, 07:22:13 PM
My diesal cherokee was blowing the same kind of expensive bubbles....stuck some steel seal in it...drove it from the UK to Poland , and done thousands of miles since with no problems....Just driven it from Poland to Kiev in the Ukraine and back...ran sweet all the way......