hey everyone. 2004 Disco2 with 150k miles on it running pretty hot. We live in Florida, so ambient temps are always hot. Our running temp sitting in traffic is 218-226 and 210-215 driving 70mph on the highway. This sounds way too hot for these motors to me, but what actually is the acceptable range? What temp should I start freak out mode with? Is 226 approaching the danger zone?

I looked at the schematics in RAVE for the fan, and it seems it has to be pretty hot for the fan to kick on (212F) and the fan wont stay on after the motor shuts off unless its over 230F. So I would assume 230F would be the line for the DANGER ZONE, but that is an assumption

I plan to do the 180 soft spring tstat next week and swap from DexCool to the green stuff. Most other coolant system pieces have been replaced recently (before we purchase the vehicle)

I scanned the ECU the other day before a long trip and the only codes were
P0171
P1174
P1171
P1412

The first said "Bank 1 too Lean", but none of the others had any info. This was scanned with a basic ODBII scanner at Advanced Auto. I cleared the codes and will scan again tonight.

So, now to the problem. My wife just texted and said the Rover stalled in the parking lot after cranking it up. Temp read 215 at start up and she said it started and ran for about 10 seconds before it stalled. She cranked it back and said it was running kind of rough, like vibrating, but it settled back after about 10 seconds.

Could a fuel trim issue or vacuum leak cause the engine to stall like this? She is driving it straight home and leaving it parked until I get there and I will assess and take it to be scanned and see what new codes we have.

What am I looking at?

Thanks!

 

That is about what a D2 was running like off the factory/showroom floor back in 03-04 as far as temps go.

Now as they've been around a while people have been using the OEM Grey 180F Thermostat and lowering their temps. However as I have experimented and learned slapping in a 180F thermostat helps until you reach the point where airflow thru the radiator becomes a problem vs the temp range of the thermostat. Say with a properly maintained OEM setup you should be 193-215F range with 204-206F as the norm. Well slap in a 180F and now you're going to have a much wider temp range say 182-210F. Not to mention ambient temps which have an even bigger effect.

Both my D2's have the 180F OEM LR thermostat, and 55-65MPH range in the summer is fine. Get stuck in traffic and the temps will slowly rise and depending on how long I'm stuck in traffic & the ambient outside temps I've seen 210-212 while in my lovely South East Texas summers with 100% humidity. Then if I cruise up to 70-75MPH temps will rise to 204F slowly, then drop down to 193F and repeat the cycle. With a stock 190F thermostat I've seen it climb to 206F, but without such a larger temp range at speed.


I say swap out the radiator while your doing the 180F thermostat especially if you're like me & have those awesome Love Bug Seasons... Those little devils are famous for clogging up radiators!! Or at least remove the clutch fan assembly and power wash it out backwards. Then yes go to the green coolant.

Also I've seen D2's that idle rough after being warmed up = usually means coolant is seeping into a cylinder. If it's rough for a bit and then goes away I'd have the coolant system pressure tested. Normally if thats the case the coolant reservoir will stay pressurized well after the engine is off & the coolant will smell like gas and your coolant hoses will be very hard if you squeeze them.

 

Thanks 4x4!

I just ordered the Genuine LR 180F Soft Spring Warm Climate Thermostat. Part number PEL500110. I think having this will help keep my mind a little more at ease regarding the operating temp. We aren't even in Summer yet and we will easily have temps over 100f with humidity in the upper 90%. It gets brutal here, and the last thing I want is the Rover fighting the ambient temps as well.

We can't afford to replace the radiator right now, but our LR mechanic said it looked to be in good condition.

We had a coolant leak, and found that the water pump was missing an upper bolt and was allowing coolant to get pushed out through the gasket. New bolt and no coolant is leaking anymore.

I will remove the fan clutch and pressure wash it when I drain the system. I need a fan tool for that, correct?

Would this be a proper flush procedure:
- Remove lower radiator hose and allow to drain all coolant.
- Refit hose and fill with water (does type matter? distilled vs. garden hose?)
- Run motor to operating temp and shut off
- Drain and repeat 2-3 more times
- Fit new tstat
- Fill system with Green coolant
This is where I am unsure. Do I run the motor again to bring to operating temp and then bleed when it's cool? Or do I let it cool down first and then bleed?

Also, do I need to bleed all of the air out of the system with each flush fill?

 

Just saw this, sorry I didn't respond to it in my previous post.

The system was just pressure tested when we fixed the missing bolt in the water pump. It held 15 psi for over an hour.

 

Just as a third party informer, I just did head gaskets on my Rover not long ago, and typically run between 187-194 under normal driving, just recently hit 208 while climbing a hill with a loaded vehicle in 80*F, and my vehicle idles choppy. It's intermittent and varies in intensity but doesn't throw any misfire codes. I'm 99% certain that I have zero coolant leakage into my cylinders so the rough idle may have nothing to do with your issue.


That being said, those Temps at highway speed would indicate to me that your have and issue that is either caused by a headgasket or will very shortly create a headgasket problem

 

The coolant usually will only seep into the cylinders after it's been running, shut down, and then restarted (say going into a store for 30min). It'll crank fine, run rough until the coolant is burnt off. Very common when you have head gasket issues.

Just drain, all the old stuff, leave the lower hose off, and keep a hose running thru the coolant jug, until the water runs thru clean or fill & drain several times.

On getting the air bubbles out I've had the best results with replacing the thermostat, filling the system, running it with the heater on until it reaches 195F (using my handy dandy ScanGauge II) then shut it off, let it cool down totally top it off thru the coolant reservoir, then carefully remove the Bleed Screw in the T (Large Flat Head has worked best for me vs a Phillips), then with a funnel top it off, and re-install the Bleed Screw. Then run it once again up to 195F and then shut it off. Once it's completely cooled down top off if needed, and top it off thru the bleed screw and that should have removed all of your air bubbles vs raising the nose up, and all that other stuff people have done.

In TX the only time I've seen 175-188F tops was during the winter months. 99% of the time it's 100% Humidity, and once warmed up it's 188-210F. The 03-04 D2 was actually made to run warmer for emission reasons and it certainly didn't help matters especially since they removed the stock Oil Coolers in 03-04 models, changed the Fan Blade/Fan Clutch to a one piece unit, and honestly in 03-04 LR could care less on improving the 4.6L as it and the D2 were at the end of their lives since the LR3 was set to roll out.

 

Wouldn't a leaky head gasket fail a pressure test? We held 15 psi for over an hour, so I would think at some point during that we would have lost pressure if there was a failure.

I scanned it after this mornings issue and it came back with the same codes as before.
P0171
P1174
P1171

i know the vacuum line to the SAI vacuum is loose and not 100% sealed, and that would make sense for the previous code P1412 thay I think is an SAI vacuum fault.

Could a leak in the SAI vacuum line also cause a misfire code for the current codes?

thanks for the tip 4x4. Garden hose method sounds like an easier plan to me.

 

It's pretty impressive that your truck has been running at those temps for this long. As far as operating temp and it's effect on the engine I will throw you this bone: when I bought the truck it was idling around 215 and made a tapping sound. In some cases that could be the steel inner cylinder liner coming loose & moving up & down or possibly something in the valve train. Either way, when I got the temps down to a 194-204 range I didn't have the noise anymore. I have read threads where others have encountered the same issue with the notion that it was definitely the sleeve as cold water applied to the block & noise ceased. It is true that temps above a certain point like 205-215 is a threshold behind principle of dissimilar metals i.e., the aluminum expands and frees the steel sleeve within. This is usually just an irritating noise but if a crack develops in the block behind the liner (not uncommon, at all) the engine can no longer run @ operating temp without overheating and the cylinder with the crack floods when it's not running and a resulting misfire occurs when the cold engine is started with a wet cylinder. There are theories behind the cracks but they happen @ anytime at this point in the vehicle's life and is extremely susceptible to cracks when replacing head gaskets and the new head bolts are torqued down; the cracks begin at the bolt taps then spread through the cylinder wall ruining the block. The lower the temp, the better. I would be puckered up if mine got up to 200f I will say that I think you are pretty brave running around @210+, it's a lot of stress on an old block with lots of revs'
The D2 rover V8 blocks are known to be poorly manufactured: the castings were off so the cylinder walls will start off within spec on 1 end as you move down the walls become thinner and thinner with less than 1.5mm separating the bores where 2mm is the absolute minimum you can have. I saw a YouTube video last week with a sectioned block showing this anomaly. Most of the 4.6 D2s are like this, the 1s still on the road may or may not have that absolute 2mm spec preventing them from catastrophically failing the rest but I wouldn't bet my $$ on it.

On another note I have posted a good flush procedure in the past, do a search on it. Your cooling system could really benefit from a proper flush & i have brought my temps down 5-deg. When the fan/clutch and radiator shrouds are off you have the opportunity to get a hose with nozzle and shoot the radiator clean starting from the top & working it across & down slowly. You will see the water turn gray where it runs off at the bottom.

 

FYI,

D2 Mx Manual says to pull block drain plugs when draining flushing.

Important step because debris, crud, etc. collects at lowest point of system and coolant needs to circulate near cylinders to cool.

You should also clean the system using a commercial product or vinegar as I used. Added one gallon & balance of water, drove for a couple of days, 100 miles, drained and did a couple of flushes with water before a final full drain removing block plugs a second time.

Did this prior to pump/clutch and thermostat change and the flush/clean lowered my temps more than the 180 stat did.

Currently cruising temps 186/188 and stop/go city traffic during summer will rise to 195.
......

 

So much diversity in the information here. One person says temps up to 225 was consider normal spec when brand new, another says don't ever run it over 210, and in another thread Spike says 230+ is the danger zone. Regardless, I realize its running hot, I am going to attempt to remedy that with the 180f thermostat and a good flush.

To ask my question again; would a crack in the cylinder block still allow the coolant system to hold pressure for over an hour?