My story:

Started truck at home for second drive into town that day
Engine rough - SES light - scanned:

P0306 Cylinder 6 Misfire Detected
P0300 Random/Multiple

Not unusual - every couple months get a misfire.
Reset codes, continued into town

SES back on and temperature gauge red light on and needle all the way at the bottom (cold), pulled over and scanned codes:

P0118 Engine Coolant Temp Sensor 1 Circuit High
P0306 Cylinder 6 Misfire Detected
P0300 Random/Multiple

Shut off, restarted - very long, rough start but it started
Turned around and drove back home (five minutes)
Parked, opened hood - steam coming from coolant reservoir cap

Remember one other time someone opened it with a glove on, so I did - glad I had the glove on - coolant erupted from the opening hitting the hood and spewing all over.

I let it cool down some, added a full jug of Peak 50/50 - still none staying in the reservoir.

Let it cool down completely, restarted - both lights on - scanned, same codes - temp. code reset this time, seems to have cooled off and is acting normally.

Drove into the shop the next day - had a rough shift and the temp dropped below low and red light came on then quickly back to normal then started overheating a few minutes later - had to stop frequently as was overheating - would let it cool down to 100 C and was back up to 135 C within minutes or less.

Made it to the shop - they've pressure tested and found no external leaks. Tried a different t-stat without success - they think it's the head gasket. The oil still looks ok in the dipper though.

Six years and around 30K miles ago we did the head gasket along with:
-camshaft
-lifters
-cam gear
-timing chain
-crankshaft seal
-crankshaft gear
-front cover gasket
-oil pan gasket
-oil pump
-water pump (done again maybe a month ago)
-rad hoses
-spark plug and wires
-belt (done again a few weeks ago)
-heads planed

Any thoughts?

If I'm in for the gasket again - anything else I need to do at the same time?

Thanks!!
TDC

 

What I guess I'll order:

https://www.roverparts.com/Parts/STC4082BK

1 O-Ring Heater Pipe At Intake BOSCH 1 Yes! $1.95
2 Gasket: Upper To Lower Intake Manifold For BOSCH Engine Land Rovers 1 Yes! $17.95
3 Gasket Intake Manifold Elbow 2 Yes! $5.90
4 Gasket - Throttle Body 1 Yes! $2.95
5 O-Ring Coolant Elbow At Intake BOSCH 1 Yes! $0.95
6 Throttle Body Heater Plate Kit 1 Yes! $27.95
7 Head Gasket Set Composite V8 1 Yes! $119.95

AND

https://www.roverparts.com/Parts/9224

1 Head Bolt 14 Yes! $55.30
2 Head Bolt 6 Yes! $29.70

 

I'd go with Lucky8's kit. Comes with most of everything including head bolts, I think I needed an o-ring for the coolant pipe going to the lower intake. It's $80 and parts are not bad quality, One of my kits lasted 80k without issue until sold. Twas a 2000 4.6 P38

You can also buy the heater plate from them. Still a good item to replace if it is not leaking.

 

if steam was coming from the reservoir cap then the cap may be bad. i believe this could cause an overheat.

best4x4 just had a post about this.

 

If you are just judging the temperature but the dash gauge I wouldn't run it until you get a device like the UltraGauge to tell you the exact running temperature. I have read and been told stories of the temp hand on the dash not moving upward until well after the truck has overheated. Could go you into much more trouble than just head gaskets if you continue to run it hot. I picked up an UltraGauge Blue after my head gasket job and it works great other than trying to get it synced up with your phone can be a hassle. I think jastutte could be right as well. I would def try replacing cap before tearing into motor! Best of luck!

 

Thanks - how can the cap cause an overheat? It was the tiniest amount of steam - almost unnoticeable

 

A cap is there as a weak link IN CASE it overheats. Now if the cap dont blow...the next weakest link does, usually, the weakest hose or gasket....or head gasket.

 

The system has to stay pressurized, if the cap doesn't seal, then things get hotter.

 

Take your cap off and drive...see if that's true. We drove our Rover for 6 months with no cap on.

It wont overheat with the cap off. It will if there is air or a major issue.

 

A misfire on #6 could be a crack block, that’s what happen to me.