Thread: Puma 2.4 coolant loss, cracked head?

Can you clarify the source of your temps in the first instance?

I'm assuming a scanguage? If so, are you reading CHT (head temp) or CWT (water temp)?

The over temp coolant limp mode cuts in at 116 degrees CWT - 109 CWT is hot but not dangerously so, 109 CHT is not really hot at all.

For info (but potentially not your issue as you have had the system pressure tested) two common coolant loss points in Pumas are:

A) the expansion cap (cheap to replace); and
the heater coolant switch - which often leaks when turned to hot on the firewall side of the valve (and is therefore hard to spot. It's also expensive).

Also, in terms of determining if you have an actual leak, it appears some TD5s always run an inch or so below the cold fill line - and expel coolant through the expansion cap when filled to the cool mark. Not sure if Pumas are the same or not?

As an aside, you can quickly check your coolant levels in a Puna while driving - just flick your heater on, if it blows hot the levels aren't too low, if they are coolant doesn't get up to the heater matrix.

It appears that I've got a similar issue to you at the moment but diagnosis is proving somewhat difficult - unfortunately I never really spent much time monitoring coolant levels previously so I (and I suspect you?) don't have an effective situation-normal baseline for coolant levels to pin any analysis I too.

I'm treading cautiously as paranoia often sets in when HGs are mentioned and rational decision making goes out the window!

I think Chook's Puma had these kind of symptoms but was actually also clearly over heating (limp mode, etc) - perhaps he will chime in as his issue was actually a HG (but from memory he had overheating issues for an extended period long before chnaging the HG).

Perhaps we both have the (very) early signs of HG failure - I better start saving for that 3./ Ranger motor!

FWIW, I've seen a couple of heads pulled overseas to find no problem - I bet that feels good...

I'll be watching this thread with interest!

Thanks n plus one,

Scan gauge measuring CwT. I didn't appreciate the ECU measured both water and head temp. I, probably mistakenly, thought that the ECU measured the head temp and the scan gauge showed that value as head water temp (the CWT value). I'll have a look at the scan gauge manual tonight.

I used to check my coolant regular and the level never budged before the temp spike i described. I was in the habit of a regular check because i had a cracked head in my previous TD5.

There is no coolant residue on the exterior of the expansion bottle. While not conclusive, i would expect residue on the exterior indicating escaping liquid.

Triumph Rover Spares in SA spares suggested a cracked port if its not showing up with an exhaust gas test. Not sure if its scare mungering but the fella said if unattended can lead to a capoot engine.

Whether a capoot engine is a risk or not, a dodgy head is not a problem i want to have to worry about touring in remote areas.

bloody defender is lining up the problems of late. And none are cheap or easy to fix.

MLD

Hmmm, yep you will get residue on the expansion bottle if it's leaking out the cap (IME).

It's worth noting that these things have an EGR cooler, which appear to be notorious for leaking in Transits. I'd want to be certain coolant wasn't leaking from a crack it in while hot before I pulled the head.

I completely take your point re remote travel, however it seems these girls typically let the HGs go slowly and steadily ( still wouldn't head off down the CSR solo without knowing it was ok though!).

PS there was a complete new donk on Fleabay the other day for $6,500...

Originally Posted by n plus one

It's worth noting that these things have an EGR cooler, which appear to be notorious for leaking in Transits. I'd want to be certain coolant wasn't leaking from a crack it in while hot before I pulled the head.

It was pressurised for 30 minutes at idle which should have shown up a leak in the EGR or anywhere else in the system.

Thanks for thinking outside the box.

If i was forced to buy a new donk, i'd increase the capacity. The 3.2 TDCi is an obvious choice. Even the TDV6 2.7ltr would be an improvement. But i'm not wishing that decision and expense.

MLD

Originally Posted by MLD

It's been pressured tested for 30 minutes and all coolant and heater hoses have been checked with no obvious leak. The coolant has been tested with that blue liquid that changes colour with exhaust gas present with a negative result. The mechanic suggested that i have a cracked head that is expanding only at and above a certain temp (i assuming under the type of conditions on the highway or sand driving).

Just food for thought, but is it a leak at the head gasket coolant gallery to oil gallery a possibility? Was any investigation made into this possible loss?

I've heard of head gasket failures where the engine oil becomes a brown, milkshake-like emulsion contaminated with coolant. This could be another source of coolant loss... but you'd likely notice a loss of 200ml/day into the oil pan.

Hi

For what is worth my 130 was loosing a bit of coolant, heater on circuit was slow to respond. The other day in 35 deg. heat blew all the coolant out together with a lot of oil.

Its just out a warranty by a few weeks so it went to the dealer. He rang me today turns out it (well per them) a failed internal oil cooler pressuring the water system.

No signs of excess temp before or after.

May be worth checking. It was a big city dealer and they have seen no other like this. My googling turned up no such thing. So probably a long shot.

Clive

Originally Posted by n plus one

Hmmm, yep you will get residue on the expansion bottle if it's leaking out the cap (IME).

It's worth noting that these things have an EGR cooler, which appear to be notorious for leaking in Transits. I'd want to be certain coolant wasn't leaking from a crack it in while hot before I pulled the head.

I completely take your point re remote travel, however it seems these girls typically let the HGs go slowly and steadily ( still wouldn't head off down the CSR solo without knowing it was ok though!).

PS there was a complete new donk on Fleabay the other day for $6,500...

I'm on my third exp tank cap this ones good it seems, I've had the exp tank changed also as it seemed to me that the seams of the tanks were breaking down (was more a precaution before a trip) I've heard the trick with the caps when they leak is to put a bit of glad wrap over the top before you place the cap on seals it tight.
As somebody said, the 2.4 tdci always sits about a cm or two below the fill to line so maybe don't fill it right up and then see if your still losing coolant.
On my 90 a lot lighter than a 130 the highest I've seen on ultaguage is 96.

Funny thing is I've been researching this as well! I get a distinct hot coolant smell sometimes from the engine bay. LR dealer tested sniffed and said that nothing could be found.
My expansion tank runs at about half full/empty so it's a tiny leak some where, I've looked and can't see a thing, my research shows it could be one of the followings:
1. Expansion tank cap
2. Expansion tank
3. Welsh plug leak
4. Minor chaffing at bottom of radiator hidden by cowling
5. Head gasket leak when engine is hot ie running for a long time between coolant gallery and combustion chamber, so no trace of coolant found.
I think if you can smell it it must be 1 of the first 4 but then again there are 20000 hoses and hose clamps!!!! Hope to find mine before it's too late.
Good luck
Mal