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MG TD TF 1500 - Waking up an engine after 17 years

Hi Everyone
I hope you will indulge me once again. I am working on a TC for another owner. Posting here as there is not much activity on the TC page and the engine is the same as a TD. I am getting the car back on the road after a 17 year sleep. I have the fuel system rebuilt, brakes sorted, new wire loom installed. The problem I'm having now, is that I have the engine turning over OK, but some of the valves are very sticky. The rockers push them down but they only slowly close. Short of taking the head off and rebuilding, has anyone dealt with this and what did you do. I have been trying to lubricate with some penetrating fluid, but it does not seem to make much difference. Thanks for any advise.

Joe Hine
J.D. Hine

Personally, I wouldn’t continue attempting to start it. You know there is a problem and you know what needs to be done. Pillar the head and have it done. Before any further attempts are made the fuel system must be thoroughly cleaned. Remove the tank and slosh it clean with a solvent that will remove the varnish. I would then clean the tank with a gross of 5/16” nuts and white vinegar over the course of several days. Drain the contents and repeat until the dumped vinegar is clear. Flush with water and then seal the tank. Moving on, all the fuel lines need to be thoroughly cleaned or replaced a
and the pump, carbs and four filter screens

If you fail to do this you will be paying the machine shop a great feat more
W A Chasser

On the subject of tank cleanin I had a local radiator guy cut a hole in the back of my tank. Needed to be quite big due to the baffles. Thoroughly cleaned sealed and then the hole resealed. Resprayed patch. Would know it had taken place. WARNING. It is dangerous to both cut and weld a fuel tank due to possibility of explosion hence why I used this particular guy.
JK Mazgaj

Incidently I have since wondered whether the hole could have been closed off with a removable plate for future checking.
JK Mazgaj

It is not necessary to cut a hole in the tank to clean and seal it. Plenty in the archives in this and the MGExp forums about the process. Threads by both myself and LaVerne
W A Chasser

I guess I wasn't the clearest. The tank has been off, professionally cleaned and sealed, new sender, painted. The copper fuel line has been well cleaned out, fuel pump rebuilt, carbs rebuilt. I'm not trying to start the car, just rolling it over on the starter.

Joe
J.D. Hine

I’ll say it again. Pull the head off and fix it
W A Chasser

I've worked on engines where the interior of the engine was very gummy. I've worked on engines where the valves were so gummy that they pulled a guide right out of the head!

Bill is right - save yourself the grief and pull the head. When stuck (as they often are), rings will often loosen up over time when fresh oil get in and cleans things out, or when they are soaked in Marvel Mystery Oil. But valves seldom clean themselves.

Tom Lange
MGT Repair
t lange

If it was your car then you have only yourself to blame for any damage to valve gear that could easily occur if you use the starter. But as the car belongs to a friend you HAVE to get him to agree to pull the head. I'd strip it, tank it, replace the rear cover with a stainless one, fit unleaded seats if it hasn't been done already, measure the cc of each of the head chambers, check the rocker shaft, the bushes and the rocker gear, measure the thickness and ensure the head is trued. Then rebuild it replacing worn or suspect parts as you go. You never know what you might discover. Cheers
Peter TD 5801
P Hehir

I've seen some pretty gummy heads cleaned out without having to rebuild them. It's easy enough to just pull the head off, remove the valves and clean everything up. If the valves, seats and guides are in good order then a machine shop doesn't need to get involved. You can do this job in a leisurely weekend of work. With the head off, it's only about an hour to disassemble and clean the valves and guides. Test the valves for leaks before putting the head back on by turning it upside-down and spraying the seat areas with brake cleaner. Then see if it's leaking into the intake/exhaust areas. If there is a notable leak then you may want to have a machinist take a look.

Also, if you're looking for an active TC forum, try mg-tabc.org
Unfortunately the TC area of this site has never taken off.
Steve Simmons

I don't disagree with anything that Steve just posted. Perhaps I should have used the word 'reassemble' instead of 'rebuild'. Much of a muchness though really. If you are completely stripping the head then the extra step of having it chemically cleaned is worthwhile. It's highly likely rust has been building up over the past 70 or so years and that it has never been tanked. A good time to have it cleaned out. Cheers
Peter TD 5801
P Hehir

Thanks for all the great comments guys. I'm just home again after a week away. I'm going to see the owner tomorrow, and I'm going to recommend taking the head off and cleaning it up. The efforts I've made so far don't seem to be making a difference. /

I'll let you know how I make out.

Joe
J.D. Hine

I just thought I would update the thread. I have taken the head off, and discovered the only valves that were stuck were the intakes. I removed them by having to tap them out, they were quite stuck. The valves stems had black sticky material on them that could only be 17 year old gas. The material dissolved very quickly with carb cleaner, I cleaned out the guides as well and everything moved freely after that. I'm awaiting new gaskets and it should go back together soon. One thing I discovered was the old head gasket was coated with blue silicon material, there were big pieces around the water galleries that were ready to fall off and gum things up.

Thank you all for the advise. Removing the head and cleaning was the best route to follow only took about three hours to have it ready to go back on.

An added bonus was I removed a big blob of jelly like stuff in the area between the thermostat and the head.

I hope to have this car back operational in time to beat the snow for a short drive.

Joe
J.D. Hine

This thread was discussed between 27/10/2020 and 23/11/2020

MG TD TF 1500 index

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