hawky666

Well-Known Member
Hello fellow members, i wonder if you can throw some suggestions towards this problem a mate of mine is having with his V reg disco td5. (is that an LR3 ??) sorry if not.

Right here we go:

This vehicle is intermittently overheating following on from the following work having been carried out in order:

Water pump replaced.

Expansion plug / core plug replaced (both following signs of leakage / failure).

Head gasket replaced with head tested prior and skimmed having failed
Test done following this and again more recently to determine if gases in water.. none found.

Thermostat replaced for new.

No sign of air lock.. all circulating as should and run with expansion tank lid off etc.. normal stuff to try and make sure.


She overheats sometimes on normal unstressed running, and othertimes with towing a trailer... but equally she doesn't do so in same circumstances. It's a complete baffling headache, especially as this vehicle is required regularly to transport horses and cannot be left stranded so is currently off the road whilst he is scratching his head :doh:

Has anyone had this sort of issue ?? and can anyone give guidance in what else to do to trouble shoot the problem towards an answer!!!.

I have asked him if his fans are actually running when this happens incase that is the problem, but he wasn't sure.

Over to you guys.:confused:
 
whats the rad like, and even after testing td5 heads not all cracks show until upto running temp
 
Rad looks pretty good John.
She was overheating previously which is why all the formentioned was carried out, and since being done, its mainly being relied upon as head sorted. Especially as no signs of contamination in water or oil etc.
I've not been with him when its done this, but i can't find any sign's of water evaporation or split pipes etc. This was also pressure tested from what i've just been informed.
 
the crack is normally on the exhaust side and pressurizes the cooling system, the oil and water dont get mixed so no tell tale mayo,
sure way to tell is fast drive down the motorway, see if it overheats, and after hard drive if coolant hoses are solid thats a pointer
you could try a new expansion tank cap as they have a relief valve in them, which can give the symptoms your having, and only costs a couple of pounds so worth a try
 
Last edited:
Could even be a cracked block, not showing for the same reasons as Johnlad says

Were the plastic dowels replaced with metal ones ? (YLL500040)

Was the refilling and bleeding done properly ?

Is the radiator hot all over it's surface area ?

Is the bleed nipple on the top hose clear and is the hose 'hard' ?
 
Thanks for this guys.
Giving me some good ideas here which i will be taking to my mate soon.
I don't know answers to some of the questions but will probably have her for a while and see if i can get it overheated to find out. My mates a very casual driver and speed isn't in his equation, so not that that causes it lol.

Keep the ideas coming.
Thanks.
 
imo start with the simple and cheaper things first, especialy if it overheats just under load and it passed the sniff test
1. take a piece of foam or a carrot and try to stop the viscous fan with engine running when the temp gauge is in the middle... if it stops that's the problem, put new viscous fan
2. put a new genuine tank cap and TIGHTEN IT WELL... if it's pressure controll valve doesnt work or it looses pressure near the 0-rings there will be overheating
3. always lift the tank above the bleed hole while refilling the system untill a clean flow comes out through the bleed hole, then with the bleed screw partially refitted keed it revved above 1500 untill no bubbles are showing near the screw
 
imo start with the simple and cheaper things first, especialy if it overheats just under load and it passed the sniff test
1. take a piece of foam or a carrot and try to stop the viscous fan with engine running when the temp gauge is in the middle... if it stops that's the problem, put new viscous fan
2. put a new genuine tank cap and TIGHTEN IT WELL... if it's pressure controll valve doesnt work or it looses pressure near the 0-rings there will be overheating
3. always lift the tank above the bleed hole while refilling the system untill a clean flow comes out through the bleed hole, then with the bleed screw partially refitted keed it revved above 1500 untill no bubbles are showing near the screw

Rolled up newspaper for the fan, it will keep your fingers just that much further away.
 
Nice one dragonwalker.. i'd like my fingers intact at the end.
Thanks sierrafery for the useful info.
 
I had very similar symptoms with my TD5 and replaced loads if parts/messed around. I thought my Rad looked good until I removed it to put a bigger intercooler in at B&W a couple if years ago. Checking the temp on Nanocom the new rad reduced running temp by 20 deg and it's been fine since.
 
Cheers accywingy.
Will Pass that on aswell.
My mates borrowed a vehicle to go away with horses for a few days so hopefully all of this will help us when he gets back.
 

Similar threads