[shastacaster]

Hi all,

1991 Range Rover with 173,000 miles. I posted awhile back about how it wouldn't pass smog, and cylinder #1 had low compression. (Original link down below)
Tore the engine down and found that the left head gasket had completely blown out, and decided to overhaul the top end.
Over the course of the last month, I've replaced both cylinder heads (brand new), head gaskets (and all other top end gaskets), water pump, thermostat, oil temperature sensor, oil pressure sensor, timing chain, radiator fan, and replaced all of the coolant hoses. Spent a while priming the engine, but the engine oil idiot light turned off after 3 tries.
Went to turn the key, and everything spun to life! It was shocking how easily she turned over.

There are two things that are preventing me from finally being done with this project and enjoying my Range Rover though:

1. After starting the engine, I couldn't see any indication that oil was flowing. My friend and I reasoned that since the oil filter, oil pump housing, and oil pan all quickly rose in temperature after the engine started, it was a sign that there is oil flow. Looking through the engine oil fill hole into the valvetrain though, the inside of the cylinder head was bone dry for a while before we saw any oil in there, and even then it was just a bit.

2. Engine temperature rose rapidly - a short drive around the block brought her close to red. Top radiator hose is hot, but not scalding to touch. I'm thinking it's either the thermostat or an issue with the radiator - I'll test this out later today

My greater concern is that the oil flow is restricted, and is directly related to why the engine is overheating. Anyone have issues like this before?
Also, since the head gasket blew out on cylinder #1 it's likely it blew because of a cooling system issue. So maybe it's the radiator? Has anyone ever had a RRC radiator cored?


Thanks

https://www.rangerovers.net/forum/8-range-rover-classic/321833-issues-passing-smog.html

 

[rangerovering]

Did you bleed the coolant system or fill it with a vac filler? If not there will be big air pockets.

If I don’t have a vac filler I run the engine with the coolant bottle open and keep topping up the level as it drops


Sent from my iPhone using Tapatalk

 

[JS5D]

The oil situation in the head could be because you assembled the rocker shaft the wrong way around. This is a little confusing, at least it was for me because I also had very little oil flow from the rockers and I was convinced I had done this right. I decided to just take the rocker shaft assembly off and study it in the comfort of my kitchen (be careful your don't drop a push rod or else you need to go fish with a strong magnet (don't ask..)). So yes I had assembled it wrong. After correctly reassembling I had a good flow at the head with plenty splashing around, but not so much that it would drop the oil pressure.

I presume your oil light is on and goes off (pressure). The oil switch can fail.

There seems to be a possible concern about priming the oil pump, there is some sort of procedure where you assemble to oil pump filled with Vaseline to ensure it primes, but what people do after a rebuild is remove the distributor and stick in a 1/2 inch socket extension wrong way around so the square hole engages with the pump shaft, use some extensions and spin it with a drill. You are driving the pump without the engine spinning and you can check for oil flow without potentially damaging your engine. Especially with the rocker assembly removed you will see the oil well up and more.

A short drive around the block without oil would have ruined your bearing shells, so if there is indeed an oil flow issue you are looking at a partial bottom end strip down again. Certainly you need to be careful you are not running your engine into the ground.

 

[JS5D]

And regarding the radiator, you can get pretty cheap ($200) aluminum replacement radiators which being new are very efficient. Old radiators can look good but can be poor at cooling even if they look clean. I think it has to do with the little fins no longer connecting effectively to the cores (and or blocked cores). It is not cheap anymore to have radiators fixed as very few shops do it and cheap (Chinese made) radiators are available, so you are looking at a few hundred buck to have somebody work on a copper radiator.

My engine overheated (barn find resurrection etc) I cleaned my nice looking copper/brass original 1983 radiator with some radiator cleaning product only to find that it still overheated AND now leaked as well. I ended up buying a aluminum radiator for a RRC, which turned out was fitted slightly differently than on my 1983 so I had to make some mods to make it fit, but engine temperature has been great since. I think they changed the radiator mount in 1987 and you should be fine with an off the shelf RRC radiator.

 

[shastacaster]

Hi all, thanks for the replies!

First thing's first, I pulled the radiator.
Didn't find anything too out of the ordinary for a 27+ year old radiator, but what was surprising was a smattering of mud caked onto the bottom of the radiator's front face.
I sent it off to be recored, should be done on Monday; at the very least the old girl deserves some TLC, even if the radiator's not the root of my issues.
Although I do hope that it is.

Secondly, to answer some questions:

@rangerovering:
I bled the cooling system, but admittedly not nearly enough. Air pockets would explain the overheating, but wouldn't there be flow issues, or wouldn't the hoses become rock-hard?
We filled the system with water for the first startup, second time around will be with coolant, and I'll be sure to fully bleed the system.

@JS5D
You helped me out a lot on my smog issue before, so thank you for that.
Mixing up the rockers was my first thought when I didn't see any oil flow into the cylinder head. The oil that came into the cylinder head is lightly covering the bottom surface, but with the engine running I don't see anything like splashing. Is this a normal condition after a rebuild, or is this how it usually is?
I downloaded the '87-'92 Range Rover Repair Manual (link below) and followed it and my Haynes Book of Lies very carefully before installing the rockers for fear of totally obstructing oil flow through the heads. The assemblies match the ones in the factory repair manual, and I confirmed they were installed in the right orientation. Plus, the domed tops of the pushrods look like a perfect match for the scallop in the rockers arms. I didn't disassemble the rocker arm assemblies as to not mess anything up, but I gave them a good brushing.
There was a healthy amount of oil coming from the oil cooler lines when I pulled the radiator, is that a good sign of flow maybe?

I'm opting for a 4-core in the radiator rebuild. I'll post here Monday night when I get it back in to share if things went for better or for worse.

https://www.landroverresource.com/docs/rangerover/Range_Rover_Manual_1992.pdf

 

[shastacaster]

Update:

As promised I have some updates.
The freshly recored radiator went in easy this afternoon; I filled the system with new antifreeze (Zerex G-05) turned the engine, and let the system bleed out any air.
Sure enough, the temperature gauge started climbing again, so much for the new radiator.
I let it cool down for an hour and tried starting it again, only this time I pulled the connector to the coolant temperature sender. Once the top radiator hose was warm (not hot, like bath water warm) I connected the sender wire again, and sure enough the temperature gauge shot up towards red.
After letting it cool down again, I pulled the thermostat and got similar results without the thermostat in there. It would seem that there’s an issue with the sender, since it’s showing high temperatures after running for only a few minutes. The sender is new though, and it would be very odd for it to be a dud right out of the box. For reference, here’s a link to the sender:
https://www.roverparts.com/Parts/PRC7918

My only other thought is that I’m still having an oil issue, and the heat is from a massive amount of friction being generated (is that possible?)
For a totally new head, is the inside supposed to look like this? Are the valve springs supposed to this dry when they’re new?

 

[shastacaster]

Further update:

Cleaned the coolant temp. sender and coolant temp. sensor connectors; temperature gauge read at just before 6 o'clock, so I think that was my issue.
Confirmed by pulling the top radiator hose away from the radiator; definitely steady flow going through the system now.
After running for 5 minutes there was heavy, white smoke coming from the exhaust pipe; no doubt coolant being burned in the engine.
At first I worried that the head gasket blew or that there was a crack in the engine block (God forbid), but it went away after a few minutes and hasn't reappeared since.
I'm guessing it was coolant that had made its way into the engine or exhaust manifold after pulling the thermostat last night, because it really got everywhere.

In any case, thank you everyone for your help. I've been working on this thing since May, and it's such a relief to see her driving around again.
If anyone else is experiencing similar issues, PM me and I'll help as best I can