Ok. on the 96 rover.

Did the new head gaskets, Truck started to over heat after. Runs great, clean full power, but over heats. Have ultra gauge and the temp will steadily rise, got it up to 230+ 3 or 4 times in testing it today.

No coolant getting in oil, or visa versa, No steam/smoke from exhaust, in fact, it's totally clean...

Noticed that the front electric fans where not working. So replaced them. Still over heating. Truck has a newer fan clutch, but replaced it just in case, no effect. Pulled the Radiator and replaced it with a newer one, testing it first to make sure it was flowing etc, still over heats. Replaced the coolant reserve, and the pressure cap, and as a final straw pulled the engine down to the pistons again to see if there was n issue with the way the head gaskets etc sealed, saw nothing. Heads look perfect, piston perfect, still has cross hatching in all the cylinder walls. Valves are all white except for #1 which had a slight orange tint (running hotter?) Went over the heads very closely and see no cracks anywhere, see no place where coolant etc would have been leaking.

Oh, we even pulled out the thermostat and ran it without one for a bit, no difference. Did go ahead and replace it.

Truck has new champion plugs, new 10mm wires etc.

The truck when first started does idle high, around 1500, but will pull down and idle at around 700. if you stop and restart the truck it idles at 700.

When the truck over heats, the top rad hose get really hard, just like it would if there was a head issue, but I think this is due to steam building up after coolant is boiled off. Coolant is only escaping via the pressure cap in the overflow once over heated, not a drop anywhere else.

Put a laser temp gauge on truck, pass side head reading was 220, while drivers side was 190... Rad and everywhere else around 220. (this was after it had been cooling down from the final overheat.)

Ran a metal strait edge on heads, and they are perfect.

Going to pull the water pump in the morning. But can see the coolant flowing in the radiator with the brass fill nut out. No bubbles, no pressure like exhaust gas is being forces into the coolant...

Guess just looking for other ideas, maybe something we are over looking...

 

Have you checked the Rad top to bottom with the temp laser?

White valves sounds like you are running lean, lean will make you run hot real hot, on a 2 stroke I melted a piston hot

A newer Rad is not a new Rad can be calcium buildup and still flow just not cool

Any codes?

Sounds like you have an air pocket,is the heater core flowing?

 

The top to bottom test should show less than 10F spread, if no sludge or calcium buildup.

The flow you see with bung out could also be the return line from throttle body heat. If coolant is real low you won't have flow thru the TB heater or the inside heater core.

With all this work, double check belt route and also check to be sure fans are all sucking a paper towel to the grille (both electric - AC on in position 2) and main fan. Don't need them fighting each other.

Hope you don't have a cracked block....

 

We filled the radiator multiple times, making sure we where bleeding it, getting lots of heat from the heater, so it would seem to be flowing.

X2 on hoping it's not a cracked block. I do have a spare if needed.

 

I had my rad rodded out for calcium last year, they unsolder the side tanks. About $75 carry in near me, look for a small indy shop that does tractors and big truck radiators. I was able to see a 5F variation top to bottom.

Then, like the fool I am, I drained it and did not flush when starting a protracted HG job over weeks. The rad dried out inside and all the mechanic in a jar stuff coated the insides (I'm a sucker for snake oil). Now I'm lucky to get a 25F spread, and she will head above 219 if parked on the hot asphalt with AC on. Don't know if I can have it rodded out again (188K). Does 183 - 187 at 60 with AC on, and it is warm in these parts. More likely will pop for a new aluminum rad at $240.

 

While looking at the original radiator, noticed it had some bent fins and was leaking oil. Ran a hose threw it off the truck and it didn't seem to have any restrictions, But I had a new Brass radiator in my 95, New as in less than 100 miles on it. It had been bought by the PO right before he redid the head gaskets, But the oil pump on that truck had failed taking the front cover with it and the truck was basically done at that point. It's the truck I'm slowly converting to diesel (slowing, like I have not had time to touch it in almost a year). Anyways there was no noticeable difference in temp top to bottom that I can remember while we where testing temps with the laser. Hard to test right now due to the engine being torn down again.

 

Is the fan belt on correctly?
What shape is the water pump in?
What is the coolant to water ratio?
Is the clutch fan facing the right way?
The electric fans dont do a thing.

 

Checking all.

One thing we did discover... (no pun intended) Is that at some point in the trucks life it's had at least the drivers head removed. The firewall has been pounded back to reach the very back head bolt.

This had to be done at the dealer. The guy I have the truck from bought the truck new and only ever serviced it at rover, (until the warranty ran out then no service).

I didn't get up to the truck today so a couple friends are working on it right now. Hope to hear more in a bit.

On the belt issue, how could you run the belt wrong?

 

There are several ways to install the belt, all look right but only one wsy is.
One way and the water pump runs backwards, another and it turns to slow, tech section.

 

Can't imagine dealer pounding away at the firewall. A socket, 3 inch extension, breaker bar, cheater pipe, and out it comes. Didn't even have to take off the hood.