I think I need to pull my heads

[Darrell_Walker]

So I've been chasing some slow coolant leaks, and trying to figure out why my
car keeps blowing coolant out of the overflow. I finally concluded that the
system was just getting overpressure, and a combustion gas test confirms that
there are exhaust gases in my coolant. There are none of the other "typical"
symptoms, the oil is clear, no oil in the coolant, temps run normal, no white
clouds in the exhaust. The spark plugs also don't have any obvious evidence
of coolant in the cylinders, either.

I tried some "head gasket fix in a can", but so far that hasn't helped. Since
I appear to be getting little or no coolant leaking into the engine, I wasn't
sure it would work anyway (if gas is just going out of somewhere into the
coolant, rather than coolant leaking into something). I used a formulation
that didn't require I remove the anti-freeze. At this point I don't know if
it would be worth trying a different formulation or not.

So, if I do remove the heads to check it out it looks like I'll need head
gaskets, valve cover gaskets, intake/valley gasket, and exhaust manifold
gaskets. It also appears there is a gasket between the exhaust manifold and
the cat, but so far I haven't found anyone that carries that (I've not looked
super hard yet). Any other gaskets that I would need? Any brands to look for
or avoid? Rock Auto seems to have good prices, and they carry FelPro.

It also appears there is some kind of sealant on the head bolts. The ROM says
to use 3M Solvent #2 to clean the threads, or trichorethylene petrol or
paraffin. It looks like 3M still makes that solvent, but it also appears to be a
professional product, so I'm not sure if I can get it retail. What common
solvents might work? I believe that paraffin is what we call kerosene in the
US, and I know that petrol is gasoline, but I'm not sure what trichlorethylene
petrol would be.

It also calls for 3M EC 776 Lubricant-sealant on the head bolts when putting
them back in. That also appears to be a professional product (and an aviation
product, at that). And also not available retail that I could find on my
quick search. Is there another product that is suitable? Is it sealing
against the crankcase, oil passage, or coolant passages?

Is there anything else I should check or do "while I'm in there"? I want to
avoid this getting out of hand, but I also don't want to tear it down again.
I will probably have the exhaust manifolds ceramic coated, and may also have
the fuel injectors cleaned.

Any other tips, tricks or pitfalls I should be aware of? What are the chances
that is is something more serious than a bad head gasket?

 

[hondo402000]

you could try laquer thinner, or acetone might work too, seems I always have a gallon of those laying around my shop and they usually disolve most anything I work with

Hondo

 

[tr8todd]

Just clean the head bolts with a wire wheel and reuse. TR8s used the steel head gaskets. Later Rover V8s used a thicker composite head gasket that will reduce your compression ratio if you use them. TR8s almost never have head gasket failures, and now you have magic fix floating around your aluminum engine clinging onto things reducing it's ability to transmit heat into the coolant. The way the coolant passages are located in the head in relation to the piston bores, makes it tough for you to get a coolant leak into the combustion chamber. Not saying it's impossible, just not likely. Check the torque figures on the head bolts and see if any are out of whack. It's possible that the engine was overheated. A more likely scenario is a cracked or slipped cylinder wall. The aluminum block has steel pressed in cylinder liners that are known to crack. You guessed it, the cylinder liners are in contact with some of the cooling passages in the block. It's more common on 4.0 and 4.6 engines than the 3.5. Either way, it looks like a tear down and possibly a full on rebuild is in your future. You do realize that the phrase "while I'm in there" is the doorway to the long expensive road to a more powerful modified TR8. We have all been there. Good luck.

 

[Brosky]

Mine had the exact same combustion in the coolant system problem and has the dreaded second option with cracked liners that Todd mentions above. Mine was so bad it was like putting the emissions sniffer on a new car tailpipe.

Needless to say, it is now undergoing a new engine rebuild and will have more HP than before.

 

[tr8todd]

Paul, did you take the engine to Bobby Mason? He just did a stroker engine for a buddy of mine, but it took a while. The other guy that does all of the Rover engines around here is in Dighton. Here is his link. Deal with him directly and save a ton of money. Ask for Joe and tell him Todd sent you.

https://precisionengine.net/

If you need someone to pull the engine and reinstall it, I'd be glad to help you. I did Dave's for him over the Winter with about a two month turnaround. Would have been quicker if it wasn't for all of the extra sorting out I had to do on his car compliments of the PO.

 

[Brosky]

Todd, thanks for the tips and offers, but it's too late now. I took it back to Woody's after the overheating and I asked him to pull it down while it was there, once we determined the the radiator was putting out exhaust emissions like my tailpipes.

 

[Darrell_Walker]

Just clean the head bolts with a wire wheel and reuse.

So no need to add any more sealant to the bolts?

 

[Darrell_Walker]

So to wrap up a few things. I got some other replies that the 3M product was an anti-seize, and that I should just use a copper-based anti-seize. Very different than what 3M sells as EC-776 today:

<div class="ubbcode-block"><div class="ubbcode-header">Quote:]
3M™ Fuel Resistant Coatings EC-776


General purpose, solvent-based adhesive/coating with good adhesion to synthetic rubber, metal, glass and many plastics. Resists oil, gasoline and aromatic fuels (non-resistant to fuels containing alcohol).
[/QUOTE]

Seems like a bad idea for them to recycle a product number. I did email 3M, and they confirmed that what they sell as EC-776 today certainly isn't an anti-seize, though were unable to confirm what EC-776 was back in the 70s.

I also found this site with some good Rover V8 information, including about the head gaskets:

https://www.v8engines.com/engine-4.htm#gaskets

Gives me hope that I do indeed just have a head gasket problem, given that the TR8 used the 14-bolt head.

-Darrell

 

[DNK]

Remember what others have said about the outside bolts.
There is a reason the later heads didn't nave them

 

[Darrell_Walker]

Remember what others have said about the outside bolts.
There is a reason the later heads didn't nave them

Yep. I've even considered loosening them now just to see if it would make a difference, figuring it couldn't hurt anything.

The site I linked shows the progression of leakage on the side opposite the extra bolts.

 

[Darrell_Walker]

Well, it has been 4 days since I got my engine back together, and no sign of coolant venting out of the overflow! I have not run the exhaust gas test, but I'm confident the problem has been fixed.

For anyone with the 14 bolt heads on your Rover V8 (which would be all original TR8 engines), I suggest keeping an eye on this. While I was getting some exhaust pressure leaking into the coolant, I was getting a lot more leaking under the valley pan gasket. I believe this was a major contribution to the amount of sludge I found inside. Apparently you can sometimes see the gasket flex up from the pressure when revving the engine.

Changing the head gaskets is a fairly major operation (particularly for an FI car with A/C), but it is a good opportunity to check out the general health of your engine.

 

[tdskip]

Does she drive any differently?

Thanks for the heads-up.

 

[Darrell_Walker]

Does she drive any differently?

Thanks for the heads-up.

Not that I've been able to notice. I'm sure there must be some difference, but just not enough to tell with regular driving.

I did run the exhaust gas test today, and it showed no exhaust gas in the coolant. I've driving it all week, and there has not been any sign of coolant venting.