Rover V8

[rovertech]

Rob,

Luck of the draw maybe. The reason I am trying to gather information is to see if there is some commonality across the board. Common mileage failure, repeat occurances etc. I have had good luck resealing the engines with no repeats (knock on wood) but I have had a lot of customers bring their vehicles to me with leaking heads within 30k of having the job done before. Like I said my work experience has been based out of the NW only and getting feedback from others who use their vehicles from across the country will help provide a point of reference.

 

[Mike_rupp]

The problems all go back to people not flushing the systems and the caustic coolant then eats its way through the head gaskets.

If people were simple smart enough to flush and change the fluid on a regular basis most head gasket issues on these motors could be avoided.

The choice to go to dex-cool just made things worse IMHO because then people thought they could leave the suff in there forever.

Thom, I have to disagree. There has to be something more to the issue than simply changing the antifreeze. The D2 V8 has an absolutely pathetic track record for bad head gaskets. There's no way you'd get me to believe that it is mostly related to fluid change intervals.

The average vehicle on the road gets it's oil changed and nothing else. Those average vehicles have nowhere near the same problems with head gaskets as the D2 V8.

 

[rovertech]

Rover never really bothered to find a way to correct the problem on a more permanent basis. BMW got sick of paying warranty claims, unloaded the company and let Ford worry about it. By then they had plans to ditch the platform so they tolerated it. Once the vehicle gets out of factory warranty they could care less anyway. Sad but true across the board I think.

 

[Brian4d]

My 02 started leaking at the rear driver side HG at 79K, indy replaced both head gaskets and now my passenger side is leaking at the front, 96K. Before you ask heads were true, new HG bolts, Thermostat and torque sequence and specs used. In erratic torquing are you referring to improper torque spec? Either way I'm in need of some suggestions at this point in time.

 

[Root Moose]

Scott, in your experience what is the best way to "solve" the head gasket issue?

Pop the heads off, inspect/replace with OEM gaskets and bolts? Refill the coolant and be happy?

Is there any merit to looking at aftermarket parts? Are there any worth bothering with? Cometic? ARP?

If one was say casually shopping for a MY04 DII would it be prudent to do the engine reseal "because" once it was brought home? (assuming it hasn't already had a history in that regard)

Just thinking out loud... in the early part of the last decade there were lots of reports of "crap" chinese fasteners making their way into manufacturing plants. What are the odds the inconsistent torque to yield bolts are caused by this?

 

[rovertech]

My 02 started leaking at the rear driver side HG at 79K, indy replaced both head gaskets and now my passenger side is leaking at the front, 96K. Before you ask heads were true, new HG bolts, Thermostat and torque sequence and specs used. In erratic torquing are you referring to improper torque spec? Either way I'm in need of some suggestions at this point in time.

Erratic torque from crappy bolts mostly. I think the factory was building some sloppy engines once they started the Thor variant which was the last, used in D2 and late P38. Question:

Had your engine overheated before head gasket replacement?

 

[Brian4d]

Erratic torque from crappy bolts mostly. I think the factory was building some sloppy engines once they started the Thor variant which was the last, used in D2 and late P38. Question:

Had your engine overheated before head gasket replacement?

Funny you ask. Answer is never. I even called both prior owners dealerships from 75K back (under warranty) and not one cooling issue ever reported.

Add: the dealer did upgrade to the new TB heater kit with second owner.

 

[rovertech]

Scott, in your experience what is the best way to "solve" the head gasket issue?

Pop the heads off, inspect/replace with OEM gaskets and bolts? Refill the coolant and be happy?

Is there any merit to looking at aftermarket parts? Are there any worth bothering with? Cometic? ARP?

If one was say casually shopping for a MY04 DII would it be prudent to do the engine reseal "because" once it was brought home? (assuming it hasn't already had a history in that regard)

Just thinking out loud... in the early part of the last decade there were lots of reports of "crap" chinese fasteners making their way into manufacturing plants. What are the odds the inconsistent torque to yield bolts are caused by this?

I don't know regarding Chinese fasteners but I think poor bolts is a likely contributor.

Cometic makes outstanding gaskets. I use them when I have engines rebuilt and blueprinted. The problem is you can't just throw them on as a service fix. They require a fine level of machine work on the block surface as well as the head in order to seal properly. I use factory gaskets with an extra layer of sealant around the oil pressure supply ring and the water jackets and use ARP head studs. This method requires re checking the torque after 500 miles or so. It adds extra expense but so far has been a very consistent fix. Aside from nice even torque with the studs you are relocating the clamping force to the top of the head and no longer asking the coarse aluminum block threads to bear the load. 4.0 litre engines have thin casting between the water jackets and the cylinder liner. When these blocks crack it is usually right along the edge of the head bolt threads between the liner and water jacket. This allows coolant to seep up and eventually penetrate the gasket. If you have a cylinder head off and you see a cylinder (usually 6 or 8) that appears to have a piston steam cleaned it probably is due to a crack. Using the studs helps relieve the stress on the thin casting.

A thor variant engine cannot "drop a liner" as the liners are pressed down onto a machined lip in the block. On a 3.9 or early 4.2 the liners could drop down and it was evident. It is possible for later engines to have liners shift following a crack in the block but this can be hard tell, the steam clean effect is a good indicator. 4.6 engines have thicker castings and resist cracking much better than the 4.0.

When Rover switched from GEMS to Bosch management the running temperature of the engines went up. It isn't uncommon for a D2 to run in the 200-210 degree range on a hot day. Not good. This is why if you have a catastrophic coolant loss or overheat, ie hose blowing, the block is probably toast. I have an intake manifold that is being modified to run a 180 degree thermostat in it allowing the relocated thermostat to be removed and dropping the running temperature. I have yet to try this myself but I am hopeful that with a retuned ECM will allow for safer running temps. I'll post pictures of this when ready to install.

Regarding shotgunning the repair. My D2 has 102k on it and I have yet to replace the head gaskets. This isn't common, but to answer your question don't fix it till its broke. Once it starts leaking do it.

I hope this flows ok.

 

[rovertech]

Funny you ask. Answer is never. I even called both prior owners dealerships from 75K back (under warranty) and not one cooling issue ever reported.

Add: the dealer did upgrade to the new TB heater kit with second owner.

A warped block surface could certainly cause an early repeat failure. If the blocks threads were not cleaned out and bolts not lubricated properly this could also be the cause. When the heads come off make sure the deck is checked for warpage.

 

[Root Moose]

Great info, Scott! Thanks.

I don't know about LRs but with the 4.0 in Jeeps D-C cranked the operating temperature to ~210 degrees as well. They did this for emissions purposes.

If you mess around with the operating temperature it would be interesting to see what that does to NOx and CO2 values at the next emissions test. We have to do it by law every two years.

 

[rovertech]

Great info, Scott! Thanks.

I don't know about LRs but with the 4.0 in Jeeps D-C cranked the operating temperature to ~210 degrees as well. They did this for emissions purposes.

If you mess around with the operating temperature it would be interesting to see what that does to NOx and CO2 values at the next emissions test. We have to do it by law every two years.

I think was common for manufacturers trying to have older engine designs meet new requirements. I am going to have the ECM retuned along with the temp drop. I will put it on the gas analyzer before and after the tune for curiosity sake.

 

[James86004]

I know you asked for them on D2s, but the 3.9 in our 89 Range Rover did not blow its first head gasket until 212,000 miles. We fixed it and sold it at 300,000. I miss that one - it was one of the best vehicles we ever owned.

The 4.2 in our 93 did it in 120,000. On that one you could smell coolant strongly in the exhaust.

 

[Brian4d]

Scott,

Not sure if I made this clear for your research. I had both head gaskets replaced at 80K and the passenger side failed at 95K.

The block seemed fine when the heads were pulled, you might be on to something with the HG bolts.

 

[muskyman]

Scott,

Not sure if I made this clear for your research. I had both head gaskets replaced at 80K and the passenger side failed at 95K.

The block seemed fine when the heads were pulled, you might be on to something with the HG bolts.

the blocks can look fine and still be junk...the only way to tell is by doing a pressure test and seeing if the block leaks where the upper sleave edge meats the deck of the block.

 

[JEFFSGTP]

I don't know regarding Chinese fasteners but I think poor bolts is a likely contributor.

Cometic makes outstanding gaskets. I use them when I have engines rebuilt and blueprinted. The problem is you can't just throw them on as a service fix. They require a fine level of machine work on the block surface as well as the head in order to seal properly. I use factory gaskets with an extra layer of sealant around the oil pressure supply ring and the water jackets and use ARP head studs. This method requires re checking the torque after 500 miles or so. It adds extra expense but so far has been a very consistent fix. Aside from nice even torque with the studs you are relocating the clamping force to the top of the head and no longer asking the coarse aluminum block threads to bear the load. 4.0 litre engines have thin casting between the water jackets and the cylinder liner. When these blocks crack it is usually right along the edge of the head bolt threads between the liner and water jacket. This allows coolant to seep up and eventually penetrate the gasket. If you have a cylinder head off and you see a cylinder (usually 6 or 8) that appears to have a piston steam cleaned it probably is due to a crack. Using the studs helps relieve the stress on the thin casting.

I will second the use of ARP Studs and Cometic gaskets (if proper prep is done for their use) in overhaul applications...worth the expense. I am interested in how your 180* conversion goes...Most of my experience with 180* (and cooler) T-stat setups has been with GM 3.8L Supercharged motors...even with stock ECM settings we found typically (for most model years) we could throw the 180*T in without any adverse effects...would be interesting to see a comparison with a stock LR ECM and then the modified one you plan on putting in it as far as main engine parameters, emissions and fuel mileage for say 1000 miles on each (unless the stock one causes issues of course). And yes I know a 3.8L GM SC motor and a LR 4.0L are two totally different beasts, but at the heart of them a motor is still a motor which is what begs my curiosity.

Subscribes to thread