[evan]

So, the truck in question is a 95 RR 4.0 (P38)- I believe I've had the trinary switch issue for a couple years, and after knocking out a couple issues this spring I was ready to look at that one. Long story short, even when it got warm, turning off the A/C would put the temp gauge back to 12 oclock. Yesterday was driving home from work (about 20 minutes on the highway) and got to the light by my house (right off the interstate) and noticed that the temp gauge light was on, and the gauge light was all the way right...

Drove about 30 seconds back to the house and shut it down. Got out and there was fluid coming out the front of the engine by the water pump, and also a good drip back on the ground by the back of the engine.

Any thoughts on what I'm facing? I've got a second car, but no garage. I figure I've got to get the fan off and look at the water pump, but not sure if I blew the head gasket. Is that likely? Is it possible it's just the water pump or the hose? Replacing the head gasket myself might be an option, but it's mosquito season here in Georgia..

Thanks in advance.

 

[RRToadHall]

Evan, you have ben a member for 5+ years. every one of your posts are "gimme" I would suggest you learn the foo of the search.

 

[leftlanetruckin]

Any thoughts on what I'm facing?

A brick wall with an imprint of your head on it....
You knew it had issues (turning ac off to get the temp down).
You apparently dont look at gauges too often.
You knew it was too hot, and continued to drive it.

Anything I missed?
Sorry, you probably cooked an engine, and deservedly so IMHO.

Martin

 

[evan]

RRToadHall -Sorry for posting inappropriately if I've done so. In the last month I've searched this site and found invaluable details about changing the starter, removing the mirror clips and diagnosing the trinary switch. I did search for overheating and found a lot of threads- I read through many and found details about situations like mine, but no one that I found mentioned specifically whether overheating more commonly leads to water pump blowout or massive headgasket failure.
leftlanetruckin - Yep, I did know I had a problem and it had been doing this for three years. It had never previously heated up at highway speeds. But yes definitely still my fault.

Anyway again I apologize for posting. I don't see a way to delete this thread, but Toad please feel free to remove. I won't post again- but I'll always be grateful for the help I've gotten here. Thanks everyone.

 

[leftlanetruckin]

but no one that I found mentioned specifically whether overheating more commonly leads to water pump blowout or massive headgasket failure.

Overheating would be more common because of a failed waterpump, not the other way around.
Massive HG failure on an all aluminum engine would normally mean slipped liner.
If you did all this searching, surely you read in passing, that these engine HATE heat? True of any all aluminum engine, but these rigs run so hot under the hood too, its worse than normal IMHO.
Only way to tell what went wrong, is to either just go ahead and pull the heads, or try a new water pump etc and slap it all back together. At this point, knowing it has run hot for YEARS, I would just start undoing bell housing bolts myself. IMHO, you'd be very lucky if the block is not toasted.

Martin

 

[stoney]

Martin, your mention that these rigs run hot under the hood.

Is it just their inherent design and bad airflow or is it from something particular? Ie exhaust manifolds or triple layer of radiators/coolers/condenser restricting flow.

Has there been some testing done on this? Ie bonnet vents or ceramic coated exhaust manifolds? Larger radiator? With benefits.

I'd rather ask here as the outcome of overheating is evident here, however I'd much rather try and eliminate the cause of the problem before it rears its ugly head, or at least try and help.

 

[desertboy]

I bought my rig back in 2007 with a possible slipped liner I missed. It had a bad Valley Gasket and it was cheap enough and I had a habit of risking on cheap Mercedes that needed head gasket work. Unfortunately, these rigs are completely different and mine blew the engine about a month after buying the car and fixing the valley gasket leak. PO must have overheated it. I got so paranoid with overheating; I did the expansion tank mod with the BMW tank and coupled the Washer warning system. With it, I have nursed a small front Head gasket leak here in Arizona heat close to an year without ever over heating.
As for your issue; can you get hold of a coolant pressure tester to pin point the leaks? Valley or Head gasket?

 

[leftlanetruckin]

Martin, your mention that these rigs run hot under the hood.

Is it just their inherent design and bad airflow or is it from something particular? Ie exhaust manifolds or triple layer of radiators/coolers/condenser restricting flow.

Has there been some testing done on this? Ie bonnet vents or ceramic coated exhaust manifolds? Larger radiator? With benefits.

I'd rather ask here as the outcome of overheating is evident here, however I'd much rather try and eliminate the cause of the problem before it rears its ugly head, or at least try and help.

I believe, and this is just my .02 here, that the engine bay has a few things going against it.
Too small an engine that has to work harder, thus making more heat.
Excellent insulation all the way around the underhood area, trapping the heat.
All the EAS stuff under there, with the compressor making some heat when it's been running a while.
I have removed the rear rubber trim on our P38, which lets some hot air out.
Hood vents/louvers would also help.
I shot the under hood area with my IR gun years ago, but cant remember what it was reading. Although., popping thr hood after a run will tell its own tales for heat being trapped in there!

Martin

 

[Rowant]

Would a contributing factor be that the thermostat is set to such a high temperature? About 92-94c if I recall.
I know that the housing is sealed but I am tempted to crack open an old one, insert a lower temp unit and have it welded up again - or maybe the lower temp would play havoc with various sensors reading ´not up to temperature´.

Any thoughts
Rowan

 

[leftlanetruckin]

Never tried it on Rovers, but on Chevy's, a lower t/stat wont allow the ECM to go into closed loop. So it runs like an old rig with a carb, and the choke half on...
We have driven ours all over the country, including the Mojave Desert in California. 5 of us, luggage, and not going slow. Never overheated one time. So, if there are issues, they need sorting out first.

Martin

 

[tompage81]

"Any thoughts on what I'm facing?
A brick wall with an imprint of your head on it....
Sorry, you probably cooked an engine, and deservedly so IMHO."

Martin you're a legend hahaha gotta love that response.

 

[RRToadHall]

I know dang wellI come across as a total douche at times but I have no sympathy or patience for folks that have been members for several years and are too lazy to search or use common sense. RRnet is not your typical spoon feeding site. We encourage, and always have, folks that use the search button and contribute. A forum is a two way street. It is not a free for all gimme gimme site for numbnuts that only check in once a year when they need something. take that crap over to DWeb with the other trash.

 

[leftlanetruckin]

take that crap over to DWeb with the other trash.

Hmmm, Discoweb, Pirate4x4, etc....Can't even imagine the responses there!

Martin

 

[hjames710]

I know dang wellI come across as a total douche at times but I have no sympathy or patience for folks that have been members for several years and are too lazy to search or use common sense. RRnet is not your typical spoon feeding site. We encourage, and always have, folks that use the search button and contribute. A forum is a two way street. It is not a free for all gimme gimme site for numbnuts that only check in once a year when they need something. take that crap over to DWeb with the other trash.

I wouldn't say you come across as a douche, just someone who's sick of seeing the same threads repeated dozens upon dozens of times. It's a waste of bandwidth, and a huge frustration. In all fairness, he had warning that this could happen to his rig, and ignored the signs.

Plus you know exactly what you're talking about, so you're allowed to be a douche if you want. I'd be hard pressed to find someone who has owned more P38's and Rovers than you.

 

[benji]

Sorry, but this is an open public forum, not some selective group. The op has said he's searched but cant find his PARTICULAR problem, and admitted he's caused the situation, yet you still speak ill of him?

If your not going to help the man dont post.

To the op.
The 4.0 litre motors had thinner walls than the 4.6 motors, and generally only takes two or three overheats to cook a block.
By all means get a hydrocarbon test done on the coolant, pressure test the coolant system, strip it down etc, but as some have said the block is most likely gone.
Itd be interesting to find out where the coolant is leaking from. The one at the rear of the block is probably the coolant overflow from the header tank.

Allow blocks get more brittle with each overheating cycle, so for long reliability id be getting a 4.6 short block and changing everything over.

Also, if you're going to strip it down be aware that the liner doesn't always move when the block is cracked.
Oh, and maybe a coolant temperature alarm`)


The underbonnet temps seem to a lot higher than the classics, I've always been tempted the remove the bonnet rubber from along the front to get more airflow. I think it's because the engine bay is well sealed and everything is packed in so tight.
With lowering the coolant temp we had an odd situation on our last trip. In lowrange GEMS shuts of the fuel to get more engine braking, but on the longer hills the engine temp dropped down to 60 sometimes. When ever it would go below 87 it would start running rich, though I don't have o2 sensors or cats.

 

[Rowant]

Firstly I must correct my previous reply about the thermostat temps. I checked rave and it opens in the low 80s and is FULLY OPEN in the mid 90s. Oops sorry.

As a starter might I suggest that you remove the fan belt and check for play in the water pump. Mine had play but didn´t leak (that I could see) when I replaced it a year ago. Also I have read that the impeller blades inside can break off if they are the plastic variety - therefore no circulation. This is just a suggestion since you say there was water coming from the water pump area.
How clean is the radiator? Just because there are no obstructions doesn´t mean it is efficient. A coating of dirt on the fins is a good insulator against heat transfer from the coolant to the outside air.

By all means do other tests that are suggested as well.

Rowan

 

[LarryS]

If you want [accelerated] engine wear (and potentially down on power) then run without a thermostat (as someone recently posted??) or if its under 70 deg. C. It runs hot (as all production cars do) so that as many hydrocarbons as possible can react with any oxygen and either turn into water or something else that the CAT can deal with (i.e it's emissions related).

The ECM will close loop almost irrespective of coolant temp, plus the O2's are heated and of course exhaust gas gets them up to temp. fairly quick too. If you watch it, it takes approx 45 seconds to go into closed loop and my coolant temp. at that point has been approx 19 deg. C.

 

[leftlanetruckin]

I was talking about Chevy engine swaps Larry, NOT about RR's specifically. FACT is a Chevy ECM wont go into closed loop until it reaches 190 degrees, so a 175 t/stat screws it all up. Last guy that had me put one in the motor I built didnt heed my warnings, which came from personal experience. He believed what the internerd said instead. He was back in a week or two to say he was sorry.
One of the many downsides of running a t/stat that is too cool.

Martin

 

[hjames710]

Looks like I need a new thermostat... I drove hard for about 2 hours today; city, highway, bad traffic, and sport mode, with the A/C on full blast in 100 degree weather. I wasn't really paying attention to my temp gauge as I was so sidetracked. Then I got the red light and a beep and pulled over immediately to let it cool off. Luckily I was a mile from home and was able to get it back after it cooled off. Checked my hoses, none were hard feeling, so that would mean I don't have any radiator clogs, correct? Just wanna make sure before I buy the wrong thing.

 

[LarryS]

I was talking about Chevy engine swaps Larry, NOT about RR's specifically. FACT is a Chevy ECM wont go into closed loop until it reaches 190 degrees, so a 175 t/stat screws it all up. Last guy that had me put one in the motor I built didnt heed my warnings, which came from personal experience. He believed what the internerd said instead. He was back in a week or two to say he was sorry.
One of the many downsides of running a t/stat that is too cool.

Martin

I never said you were, just that info was so far from what the Rover does (and all others afaik) perhaps it's worth pointing out. That said, what decrepit Chevy ECM needs it to be that high?



***you also don't really want to remove rubber trim that seals the engine bay, as you don't want to do anything to lessen the [high] pressure difference in front of the rad and that of the [low] pressure behind it, hence all those little trim pieces around it. RAVE itself say's the ram air effect does the majority of the cooling (whilst going obviously).