1999 P38 - Overheating periodically

[siflying]

Problem ? Vehicle has been overheating periodically over the past 18 months (very often lately) with no resolution despite taking it to 3 different mechanics. I have been able to drive it most of the time, trouble free, but it randomly overheats with the red dash warning light coming on and water overflow from underneath. Various hoses have exploded, most recently the ?S? shaped hose leading from the coolant reservoir is expanding when hot.

Also loud clicking sound in engine seems to be getting much worse?am told could be cam lifters or liners worn. Is tis related?


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Vehicle History

** Related pre-purchase work completed by JRG Automotive included: New Radiator, New Water Pump, New Thermostat, Top Radiator Hose** in 2011/12

Aug 2013
Purchased with a Pre-Inspection report by Deacon Automotive.

Pressure Tested Cooling System ? Passed.

May 2014
- Driving locally on very cold & wet wintery night with heating cranked ? Engine overheated. Took it to Deacon ? Returned 2 weeks later with replaced Thermostat
- 3 Days later, 5 way hose exploded and water gushed everywhere;
- Did not return to Deacon and instead took it to Toorak Tractor on the recommendation of another RR enthusiast;
- 3/6/14, picked up vehicle with replaced hose. The next day it exploded again!;
- Towed back to Toorak Tractor. He had the vehicle for 9 WEEKS'stated that he pulled engine apart, checked and refit head gaskets (not machined) and also said he cleaned radiator thoroughly, pressure tested etc

May ? June 2015
- Overheated for the first time since 2014. Took it back to new machanic (Jobson Electronics) on several occasions as problem kept re-occurring.
- Water Pump replaced; Thermostat replaced, Thermo Clutch Fan repaired; Hose(s) replaced; Heater Core repaired/replaced.
- Heater now works perfectly as was also faulty.

June ? Present 2015
- Regularly over-heating. Jobson advised to flush high-pressure water via a hose through the water reservoir and out through the small top hose from the radiator. I have been doing this repeatedly to buy time. For the most part, the vehicle drives fine, but can overheat at anytime.

I am replacing radiator cap (slightly worn) and 'S' hose on Monday.

Any help appreciated or at the very least a great mechanic in the Melbourne area who could be recommended?

[p38arover]

I had the same problem with mine. Hoses, thermostat, and radiator replaced and it still would suddenly boil and throw out the coolant.

How hard is the top radiator hose after driving for a while? Is it pressurising the cooling system?

DO NOT drive it when it is overheating although it may now be too late. These engines do not take kindly to overheating. Ticking noise? Might be a slipped liner.

Google "Rover V8 slipped liner"

[davidsonsm]

Has the expansion tank cap been replaced with oem new one?

[siflying]

Has the expansion tank cap been replaced with oem new one?

On Monday, have ordered new one + hose that is connected to it underneath....

[siflying]

I had the same problem with mine. Hoses, thermostat, and radiator replaced and it still would suddenly boil and throw out the coolant.

How hard is the top radiator hose after driving for a while? Is it pressurising the cooling system?

DO NOT drive it when it is overheating although it may now be too late. These engines do not take kindly to overheating. Ticking noise? Might be a slipped liner.

Google "Rover V8 slipped liner"

Good point, if I squeeze it, often its not hard at all immediately following it overheating....that is I can squeeze it all the way....I guess this would suggest water not getting to radiator or just air in the line?

[TheTree]

Good point, if I squeeze it, often its not hard at all immediately following it overheating....that is I can squeeze it all the way....I guess this would suggest water not getting to radiator or just air in the line?

That's a good sign because if the hose was hard it usually means that you have a leaking head gasket, cracked head or cracked block

Steve

[Pedro_The_Swift]

worth a quick read--

http://www.aulro.com/afvb/good-oil/92065-refilling-radiators.html

[Scouse]

Blowing hoses means that the system is overpressurising. If the workshop has tested the cap (and I'm sure they would as a starting point??) then you have bigger internal issues.


One reason the hoses might not be hard after overheating is that the pressure has escaped when it lost it's coolant. Try the hoses before it overheats.

[DT-P38]

Try AMV in Ringwood if you are out that side.

[TheTree]

Blowing hoses means that the system is overpressurising. If the workshop has tested the cap (and I'm sure they would as a starting point??) then you have bigger internal issues.


One reason the hoses might not be hard after overheating is that the pressure has escaped when it lost it's coolant. Try the hoses before it overheats.

I meant to add this as well!

When the beast is at normal temperature and with the engine running, feel the hoses and see if they are hard

Steve

[TheTree]

Quite a few of us on the forum have fitted Aussie Desert Cooler Radiators to beef up the cooling system.

But these periodic episodes sound weird.

Reading through it seems your radiator has not been replaced, just tested etc, is that the case?

Steve

[siflying]

I meant to add this as well!

When the beast is at normal temperature and with the engine running, feel the hoses and see if they are hard

Steve

Firstly, just replaced coolant cap and S hose leading from coolant as this was balloting when hot.........

For the most part, no the hoses are not hard..I can squeeze the larger hose going directly into the radiator all the way

[banarcus]

A few questions:
Does it get hot when driving at speed or at a standstill?
Does your expansion tank/coolant reservoir rumble or have bubbles in it?

A handy little thing to have is a OBD2 ELM27 device to plug into your diagnostic port and then download a handy little app called Torque. You can then read the exact temperature that the ECU reads from the sensor. Better than the dumb gauge on the cluster.

From experience I can say that your overheating coolant was at least 115deg which builds up anywhere between 15 to 20 psi of pressure.

If you have bubbles, a hard radiator hose or a rumbling bubbly coolant tank, you have combustion gases in the cooling system.

You can have a brand new radiator, water pump, fans, thermostat and hoses etc but you're wasting your time and money if you have combustion gases getting into the coolant.

It will only get worse. I'd be taking off the heads and checking the old head gaskets and also the heads for warpage. In addition, it's likely you have a slipped liner in your block.

[siflying]

Okay had engine running at normal temp (mid way point)...hoses are soft including main hose going into radiator i.e. I can squeeze them no problems....

For your interest..just replaced coolant cap and S hose

[TheTree]

There is a test for exhaust in the coolant, my local workshop did one for me pretty cheaply.

Might be worth doing to confirm that the heads etc are all OK

Steve

[siflying]

I meant to add this as well!

When the beast is at normal temperature and with the engine running, feel the hoses and see if they are hard

Steve


A few questions:
Does it get hot when driving at speed or at a standstill?
Does your expansion tank/coolant reservoir rumble or have bubbles in it?

A handy little thing to have is a OBD2 ELM27 device to plug into your diagnostic port and then download a handy little app called Torque. You can then read the exact temperature that the ECU reads from the sensor. Better than the dumb gauge on the cluster.

From experience I can say that your overheating coolant was at least 115deg which builds up anywhere between 15 to 20 psi of pressure.

If you have bubbles, a hard radiator hose or a rumbling bubbly coolant tank, you have combustion gases in the cooling system.

You can have a brand new radiator, water pump, fans, thermostat and hoses etc but you're wasting your time and money if you have combustion gases getting into the coolant.

It will only get worse. I'd be taking off the heads and checking the old head gaskets and also the heads for warpage. In addition, it's likely you have a slipped liner in your block.

Yes, overheats at speed, not standstill....and
Yes I can hear the coolant reservoir rumbling through the dash especially when its about to overheat.

By the Way...just had a test at the local mechanic...confirmed that combustion gases are in coolant as testing unit turned yellow from blue.

[banarcus]

You will at the very least have one, maybe two blown head gaskets around the water jacket adjacent to the rear cylinders. Hopefully you haven't got any slipped liners.

[TheTree]

Hi

I'm not sure how involved you want to get but one thing you can do is to purchase a borescope camera (cheap off ebay) and inspect each cylinder through the spark plug hole

This can often provide more info as to the nature of the issue.

Steve

[p38arover]

But these periodic episodes sound weird.

Not to me. I went through exactly the same problems with mine in the early days of ownership - before slipped liners were well known.

We tested for exhaust gas in the coolant. Nothing.

We pulled the heads thinking head gasket problem. Nothing wrong there but we did a minor rebuild then (new cam, lifters, valve guides, etc.).

This intermittent sudden boiling went on for a long time before I bought a secondhand engine and fitted it.

Eventually, I had the original engine fitted with tophat liners and refitted it. That's what's in the car now.

[Eevo]

Hi

I'm not sure how involved you want to get but one thing you can do is to purchase a borescope camera (cheap off ebay) and inspect each cylinder through the spark plug hole

This can often provide more info as to the nature of the issue.

Steve

this method generally wont pick up a cracked block though.
i tried it.

[TheTree]

this method generally wont pick up a cracked block though.
i tried it.

When I had the stuffed motor we could see that it was number 3 which had coolant in it, that confirmed a cracked block. So I put some rislone in it while i sourced another motor.

If it is in 7 or 8 it's more likely to be a head gasket

But since this needs to have the heads off it may be a waste of time to do the borescope thing

Steve

[p38arover]

Also, read this: http://www.aulro.com/afvb/l322-range-rover/206748-expansion-tank-radiator-cap-part-pcd000070-use-genuine-land-rover-parts-only.html