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MG MGA - Engine block drain
| I am putting my coupe away for the winter, just got the engine running, and am trying to drain the engine block. I cannot remove teh block drain valve, but I can open it. I could not get a wrenh on the valve body to remove it, so I plan to blow air into the valve to remove any water present. Should I remove the valve, o rsould I get some anti freeze and mix and then drain the radiator? The radiator hoses are absolutely shot, so it would do no good to plan on keepin colant in the engine. Thanks. |
| Mike Parker |
| Mike, I believe a crow's foot with an extension bar will grip the block drain valve body. -M.S. |
| Martin Straka |
| Martin, I will have to look for a crows foot in my tool box. Maybe, maybe not (whether I have one or not) Didn't think of that. I did try flare wrenches, but can't reach with them. I may have to buy some cheap flare wrenches(just got rid of em when I got good ones, drat) and grind the right one thinner, maybe torch and bend? Thanks. |
| mike parker |
| A good rule of thumb is to never give away or sell a wench or even a wrench. Sooner or later you will miss it. Sandy Sanders |
| conrad sanders |
| I'd replace the hoses and leave antifreeze in the system. All that air in the wet passages is sure to cause corrosion, and you could end up with dried out seals too. |
| R. L Carleen |
| Mike My car has a 40% mix of antifreeze and distilled water, the distilled water doesn't corrode as much as ordinary water, as advised, its best to leave it in during the winter. |
| Terry Drinkwater |
| RL and Terry, Thanks, this does make sense. Sandy, the wrenches I got rid of were made in China, and not of any outstanding quality. (just what I need right now, I know.) BTW, I didn't know that about wenches, thanks. |
| mike parker |
| Conrad...in most states it is illegal to sell wenches. =0( |
| Jon Bachelor |
| Mike You will have to get the valve off if you are not putting in anti-freeze. If you are not using A/F at all the engine will be corroding nicely, especially the thermostat housing. A/F has inhibitors to protect against corrosion. So behind that valve will be solid sludge. You will need a whitworth spanner on the valve. It will be useful to remove a spark plug or two and the oil pressure flex to give a bit more room. When I first got my 59 MGA, having unscrewed the valve, I had to drill out sludge to about 2 inches deep with a 3/8" dia drill before any water trickled out. Having had the waterways steamed out and using distilled water with 33% A/Freeze for the last 7 years, changing every two years, all has stayed clear. If you want the correct spanner size come back and will see which size fits for you. Peter |
| Pete Tipping |
| I spent about 2 hours picking and scraping solidified gunk from the valve up to the jackets. And that was with all the tappet covers and freeze plugs out during a rebuild recently. I cannot for the life of me imagine doing this with the engine in place. Oh The horror! I they made Marlon Brando and Martin Sheen do this as a screen test to see if they cut the mustard for Apocolypse Now. |
| Ken |
| Hi Ken No engines come out to get their waterworks steamed out with all core plugs removed! Peter |
| Pete Tipping |
| Peter and Ken, I do have the slightest trickle when the valve is open, but I am not comfortable with it. I will try to work on it whis weekend. Thanks |
| mike parker |
| Pete , I am not sure if I catch your meaning but I pulled the freeze plugs out to get better access to clean the passage ways. I did not dip my block when I did my rebuild so maybe that is where you are confused!And certainly I did not pull the engine to only clean the passage ways. Mike, I agree that a trickle is not very satisfying but it took me about an hour of picking to even get that! Ken |
| Ken |
| Ken, Reading past posts on the procedure, I was pretty happy too; that is why I feel that I should take out the valve and drain it there- to clean any more that I can. I don't want to take off the oil line, so we'll see what I have to do. I did get the starter out without removing the oil filter assembly, which I have read that you can't do, so maybe I can do this too. |
| mike parker |
| Hi Mike, You might have an easier time of it since there exists a passage way to start with. I found that 80% of the crud was in the elbow that turns up into the jackets. Some of the last I was able to get thru the freeze plug holes working from above. I took an old screwdriver and continually bent it to work my way into the elbow. Its a bitch of a job. Good Luck!! But you'll feel so good about yourself after you are done! My wife said I had a glow that lasted for days. |
| Ken |
| Ken, I know, by what I have read, that it is not an easy job. I certainly don't look forward to it, but, it does have to be done. Thanks. I don't think it can be much worse than my 59 Ford, the first car I owned. I pulled the replacement rubber freeze plugs and couldn't see the cylinders for the rust! |
| mike parker |
| Just add my 2c. I took my drain tap out with a lot of scraped knuckles using an A/F open spanner (or maybe metric). I seem to remember having to turn the spanner over for each turn. It may not have been correct but it did the job. Like every one else, I found that it was blocked up behind and cleared it using a selection of drills and bent wires. I also attacked it through the water passages from the top as the head was off at the time. At no point was the engine out of the car or anything disconnected from that side. It can be done if you're persistant. |
| Dan Smithers |
| Once you get the valve out and the trickle increased to a stream: make up some way of adapting a garden hose to the fitting on the block; take out the thermostat and leave the radiator hoses disconnected; back-flush the system until all the water comes out clean. A bicycle spoke makes a good 'poker'. |
| Fraser Cooper |
| I have also used short piece of speedometer cable in an electric drill and let it wobble all around. This would be a good place to utilize a WENCH. Sandy Sanders |
| conrad sanders |
| Sandy, I am sorry(you don't know how)but I don't have a wench available. Looks like I have to do it myself. Fraser, good idea, especially since the t-stat is missing right now. Dan, I appreciate the knowledge, so now I know that I can do it. Thanks all. |
| mike parker |
| Hi Ken When I first got the "A", as I say, the jacket was full of muck; and then there was no thermostat, leaking core (freeeze) plugs and I had sourced a needed replacement gearbox. Being a bit busy myself, it went to my man. As the engine was coming out anyway, it was decided the waterways were going to get that clean-up they needed. Them professionals steam it all out. Makes sense to me, the mess must be horrific. It works too as it's still just fine and the engine got a nice paint-up at the same time! Peter |
| Pete Tipping |
| Hi Pete, You are right in that the mess is just short of horrific. Good thing you had your guy to do it! I think one might be able to open a passage way with steam and pressure but some of the stuff that I pulled/drilled/picked/gnawled at seemed to be as hard as the block itself and I doubt that a simple steaming would have removed it all. I had the feeling that I was removing things that spent the better part of 30 years getting the way they were. Mechanical cleaning is the only way to get rid of it in my opinion. Although I'm sure that not all cases were as bad as mine. Ken |
| Ken |
| I have cleaned rusted parts with white vinegar with good success. Has anyone considered dumping a gallon or so into the cooling system and letting it soak for a while? The drilled hole leading to the petcock is a small size so it might take a while to open it up. Mark |
| MLS Somers |
| Mark Check the MGA Archives for "Cure for overheating' or just search on "vinegar" Answers your questions. HTH Larry 58A |
| Larry Hallanger |
| It probably is best to have the engine professionally flushed, but if you are a risk-taker, you can try oxalic acid. It is the active ingredient in over-the-counter radiator flush, but you can obtain a much higher concentration by buying powdered deck cleaner (look for the ingredients on the back). Just first remove the thermostat, then make up a concentrated solution, pour it in, and run the engine for about 15 - 20 minutes until it reaches operating temperature. For a heavily rusted system, drain and repeat until it looks like no more particles are draining. The system should be flushed with water until clear after treatment. At the risk of heresy, I'm not a particular advocate of using distilled water simply because there is so much base metal in an engine that the water rapidly picks up soluble ions and rapidly becomes conductive. The additives in normal antifreeze are sufficient to inhibit rust and prevent corrosion. I guess the use of distilled water in an automotive cooling system a matter of individual comfort level. (Batteries are another story altogether.) Since there is no aluminum in the system, you won't cause corrosion problems using this approach. (The worst that can happen is that you will loosen so much crud, that you will actually block a water passage before the oxalic complexes and dissolves the rusty iron. That's why it's good to use pressure during the cleaning process. Steve |
| Steve Brandt |
| Steve, I think that the advantage with the distilled water is that the calcium and manganese in the water will not be there to plug up the radiator passages. I don't think it really matters regarding the engine. BTW, waiting on new hoses to install on the engine, and then in goes the antifreeze. |
| mike parker |
This thread was discussed between 02/11/2004 and 13/11/2004
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