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MG TD TF 1500 - Sump Magnet?

Anybody see a problem with using one of these? I know that purpose built sump plug magnets are available, but at a cost. Half a dozen of these came from an appliance, not sure which, possibly a microwave oven and were being tossed out, so cost nothing. I can't see any reason why I shouldn't fit one of these either on top of the sump baffle plate or underneath it. The crank clearance is my only concern if mounted on top, so its probably better mounted below the plate. It would stay put as it's an incredibly strong magnet and picks up a 12" spanner off the bench from about 3/4" away. Given the size the chances of attracting stray bits of metal would have to be much greater. The only down side is that I'd have to remove the sump to examine it. But I don't plan on generating metal filings... And most cars don't have magnets on sump plugs anyway. Cheers
Peter TD 5801



P Hehir

Do it right. Tom Lange sells good stuff:

https://mgtrepair.net/DrainPlugs.html

Jim
J Barry

No argument Jim about the quality of Tom's stuff, but that doesn't address my question. Anybody see a problem with this approach? Cheers
Peter TD 5801
P Hehir

Endorse the comment re Tom Lange’s plugs, I have all 3 in the set.

Drop the sump to check a magnet, seems like a task created to fill time available. Especially if you have lots of time...
P G Gilvarry

Not suggesting the sump be dropped, in fact I thought I stated the opposite. Anybody care to address the question? Cheers
Peter TD 5801
P Hehir

“The only down side is that I'd have to remove the sump to examine It.”
P G Gilvarry

I think I mentioned in your sump welding thread that when I had the stripped drain plug replaced with an aluminium hydraulic pipe fitting the sealing cap that goes with the fitting is steel and I simply dropped a rare earth magnet into the cap. I pondered, as you are doing, the chances of it coming adrift and the 100 or so km since it first ran have so far confirmed that it hasn’t!
Not exactly your situation but, provided it has clearance I can’t see a problem. If the sump is off the car, would it be possible to put the magnet under the plate?
Chris
C I Twidle

Hi Chris. Yes I do recall your post. The sump is off the car and is part of the standby engine that I'm rebuilding. I just had it successfully welded up as you saw and have a written a piece based on my observations and research on that task for the June issue. While I have the baffle off it seemed a good opportunity to mount this magnet on the underside, as I didn't want to risk fouling any of the moving parts. The other considerations are interfering with the flow of oil to and around the pick up, so some thought needs to be given to its location. I can't see any other downside. This is an extraordinarily powerful magnet (see the pic) and it ain't going to move. It takes two hands to shift it from the stack of six! Obviously it was never my intention to remove the sump for regular inspections. Suggestions to that effect are beyond idiotic... My thought was that it would sit there undisturbed forever and a day; or until it became necessary to remove the sump for some pressing mechanical reason. Thanks for your post. I shall proceed. Cheers
Peter TD 5801
P Hehir

Peter
Nearly all Japanese transaxles have a magnet just like than inside them and most auto transmissions have them inside the pan as well
As you say there shouldn't be any metal floating around and you can't service the magnet BUT every transmission I've pulled apart with one the magnet looks like a bottle brush with all the rubbish stuck to it-
I'd epoxy it to the bottom of the sump near the pickup but out of the way and let it go fishing , won't hurt having it there and might just save a bit of 'something' going through the oil pump
A magnet in the drainplug would naturally be easier to clean and show if something was going wrong but I can see the benefit of having one of your donuts in there
They're really interesting when they've got a lot on them the stuff lines up in rows






William Revit

I don't see any real problem so long as it stays put. But I would rather have it on the drain plug so that you can inspect it at each oil change. Inside the sump, it will simply collect all the ferrous bits until the day the engine dies, without ever telling you there may be a problem. Even without a magnet you sometimes get debris out the drain plug, but a magnet inside will likely hide most of it. Perhaps not an issue, but I'm more comfortable with the magnet in the plug. You can always epoxy it in there instead.
Steve Simmons

The ones that I make for the rear axle are an interference fit + epoxy. I don't trust glue alone.
Regards
Declan


Declan Burns

I bonded a strong magnet to the drain plug, which seemed to work well, but I noticed the magnetism had deteriorated significantly. From what I have read, this is not unusual and its better to use the type of magnet that is less temperature sensitive, such as Samarium Cobalt.
Dave H
Dave Hill

Thanks Steve and Willy. It does me good to see responses on topic, without rancour, that actually address the question! Steve it's a bloody big magnet nearly 2 1/2" across so impractical for use at the sump plug. I can see the value in one of Tom's jobs and may well get one, but that wasn't the question, as you, Willy and Chris figured out. The image of the donuts picking up metal from the automatic transmissions on Japanese cars was a real eye opener Willy and I'll now definitely go ahead! The sump baffle is steel so the magnet will stick to the underside at least as well as epoxy, if not more so. I doubt that even two strong hands would be able to shift it without considerable effort. Thank you gentlemen; the question has been now been answered. Cheers
Peter TD 5801
P Hehir

Peter
Just for the record the dark pan with the 2 fluffy magnets is --------------------------------mercedes
William Revit

That's a bit of a worry Willy. If a top of the range vehicle like a Merc sheds metal then the magnet at the plug of the lowly M.G. is a worthwhile investment. It wont catch much given its size and location away from the pick up but it will indicate that metal is being shed. Correct me if I'm wrong, but my guess now is that this is actually happening in every vehicle. Obviously the bigger the magnet the more metal particles it will attract and the less metal will find its way back to and through the pump. It should also prevent the screen from clogging prematurely; so as you say the installation of the doughnut has to be a good thing. The Samarium Cobalt has me intrigued Dave. I'll Google it tomorrow. If the magnetism ever does deteriorate I'll hear it rattling around in the bottom of the sump, but I don't see that happening in my lifetime. Thanks guys. Much appreciated. Cheers
Peter TD 5801
P Hehir

I made my own sump plug magnet using a neodymium magnet set into a shallow hole in the original plug and set in epoxy.

When considering your magnet you need to ensure it has an appropriate heat rating. See some info below. I don't think in the bottom of the sump the oil is ever going to get excessively hot. However given the unknown origin of the magnet you are using I would go with expoxy and not just rely on the magnetic force alone :)

Dave

https://www.first4magnets.com/tech-centre-i61/information-and-articles-i70/neodymium-magnet-information-i82/how-does-temperature-affect-neodymium-magnets-i91
D Moore

Hello all

Why not put some cheap chinese magnets (or even cheaper: an old speaker) on the outside of the oil filter? Most oil should come there, particles stay inside the filter and magnets outside. That makes cleaning easier. I do it on all my cars.
Marcel Schaepman

There is something quite satisfying in removing magnetic fluff from a sump magnet, and it is a useful tool to demonstrate there is something going on inside the engine.

An external filter magnet gives none of that feedback.

Tom Lange
MGT Repair
t lange

Interesting chart Dave. Anyone know the operating temperature of the oil in an XPAG. That will enable me to ascertain the effectiveness of the neodymium magnets (the doughnuts in a microwave) and the potential loss of magnetism over time. No argument from me Tom. Marcel one major advantage of the larger magnet in the area of the sump pick up is that it protects both the screen and the pump more effectively than either the externals on the outside of the filter canister or the small one at the plug. Sure there is no visual indication but the more particles that a larger magnet can prevent going through the pump, the better. I still can't get over the amount of metal harvested by the doughnuts in the Merc pan! Cheers
Peter TD 5801
P Hehir

Peter
I've been thinking more about your magnet and think now that the best place for it is epoxied to the bottom of the sump as earlier thought
If you had it on the baffle plate, then the plate will have some magnetism and particles could stick on the top side as well which could be a bit messy
Better off right down the bottom --
As far as oil temp goes , most racers aim for around 90 deg C as a max and to run at that temp is the norm. A T type would probably struggle to get that high normally with the large amount of oil in a tiny engine
The Merc pan magnets in the pic were the result of a needle thrust race failure
Electronic auto transmissions use strong magnets , some have three or four, to try and attract any metal debris, otherwise it goes straight to the shift solenoids and can/does short out the wiring connectors playing havoc with gear changes etc
A real regular sufferer of this is the 4speed Falcon boxes that have their S5 variable solenoid excited at varying degrees all the time and is a real gunk magnet--till it shorts out

My vote--glue it on the bottom
William Revit

OK Willy. Logic rules. Your vote wins! Cheers
Peter TD 5801
P Hehir

I have a 1948 TC with XPAG (40 over) with a Marshall J75 Supercharger and an oil temp gauge. Oil temp is usually about 5 degrees c lower than the cooling system that runs around 85 degrees under normal driving conditions.
gl rombough

Willy - seems to me you are are positioning your magnet right where the drain plug magnet would be...

I don't think I would ever have the energy to remove the sump just to check on a magnet epoxied to the bottom. And heaven help your engine if it ever came free - despite their great reputations and myriad uses, I have seen both Araldite and J-B Weld fail.

I'm sorry, but this discussion feels like a solution in search of a problem.

Tom Lange
MGT Repair
t lange

Magnetic plugs are the norm in jet engines, the ones I used in the military had 2 magnets that when bridged brought on a light in the cockpit and we would shutdown the offending engine.

Later in the pure Jets there were magnets inserted in the return lines from each bearing to allow analysis of engine wear. They were replaced at intervals and sent off for analysis of any metal and also analysis of the oil.

I have Tom Lange plugs in my gearbox and differential, engine will have one real soon.

Is this thread a case of a magnet looking for an attraction?

Peter
P G Gilvarry

Too true Tom, a drain plug magnet would be more serviceable for sure---The advantage of it being such a strong magnet would be when/if something drastic happened then hopefully it might save a load of junk going through the oil pump etc
If it did come unstuck I imagine it would find it's way to the pickup and stick itself there--
The negative is that it's not easily servicable-
A nice strong drainplug magnet would probably be best choice, and more servicable
Cheers
willy
William Revit

Tom. I have three sumps sitting here in front of me in the lounge room (I have a very supportive partner) and I can tell you, as I'm sure that you well know, that the sump plug is on the SIDE of the sump, well away from the pick up. As was clearly stated earlier, it was never the intention to install the magnet as a means of checking for disintegrating metal!! This was made really clear with my statement on the earlier post that "Suggestions to that effect are beyond idiotic..."

Araldite and JB Weld have never been mentioned in this thread in relation to adhering the magnet to the bottom of the sump. There are an abundance of epoxies that are eminently suitable for this application. I don't propose to list them. For some odd reason we now seem to be AGAIN moving away from the original question. Could I please ask you to stay focused folks! Cheers
Peter TD 5801
P Hehir

Peter - I confess your response is puzzling: your ONLY question was, "Anybody see a problem with using one of these?"

As I re-read the entire thread, almost every answer has provided a suggestion on one side or another to that question, and that the consensus seems to be that a sump plug magnet is the better solution.

And to say that these engines do not shed magnetic hair seems the most "beyond idiotic" suggestion.

Your posts suggest you already know what you want to do and are disinclined to listen to any other suggestion. So why bother asking the question?

Tom Lange
MGT Repair
t lange

It is possible to perform analysis of automotive engine oil, that would give early warning of trends in wear.

This is very common in large engines used in industry to nip any issues in the bud.

NAPA sells a kit to have this done, not expensive. Has anybody done this?

Peter
P G Gilvarry

Tom, with the greatest of respect, your summation "and that the consensus seems to be that a sump plug magnet is the better solution" is an opinion, just an opinion, your opinion. It isn't a solution.

The question was "Is there an issue with installing one of these"? The answer was clearly NO! There were opinions expressed that suggest that it was unnecessary, as there were sump plugs with magnets available, such as the ones that you sell, but you don't give them away. They come at a cost. The magnets that are free and come from a dumped microwave oven obviously CAN be used and will do a better job of harvesting metal particles than your plug for three of what I see as important and self evident reasons; apart from the fact that they cost nothing:

One. They are significantly larger and can be placed closer to the oil pick up.

Two. They will do a better job of harvesting metal particles that the smaller magnet that you sell attached to the sump plug on the side of the sump.

Three. Any means of preventing metal particles from entering the oil pump WILL enhance the longevity of the pump and so has to be a good thing.

If this wasn't the case why would the major makers bother to go to the expense of installing multiple large doughnut magnets in the pans of transmissions and sumps and not simply rely on a single sump or pan plug magnet? The answer that Willy provided says it all...

Finally you and Mr Gilvarry have obviously both clearly misunderstood the comment in relation to the purpose of the magnets. IT WAS NEVER INTEND TO BE USED AS AN INDICATOR OF THE HEALTH OF AN ENGINE!!!! Also, if you re-read the series of my posts, you will be forced to admit that I have only had positive things to say about the use of your magnetic plugs, as an INDICATOR! What I'm suggesting goes much further. These magnets are HUGE! Almost 2 1/2" inches in diameter and approximate the size of the multiple magnets used in more modern high end cars, where prevention of damage; such as feeding metal particles into shift solenoids in Mercedes transmissions; or the oil pump and/or blocking the pick up filter screen, clearly overrides any 'indication' provided by your sump plugs. I sincerely hope that my position is now crystal clear. I do welcome further posts on topic that actually address the question that was initially asked. Anything else, I'll simply politely ignore. Cheers
Peter TD 5801

P Hehir

Hi Peter,
Your plan could prevent some problems being detected at oil change times as others have suggested. If you later decide to fit a sump plug magnet, it won't be a reliable problem indicator. After a bit of mileage, the weight of it, with engine vibration, could also cause the baffle plate to crack.

Apart from the metal sludge it collects, I once found two oil pump teeth on the sump plug magnet. (After a pump shaft circlip had failed, the teeth had been knocked off by the #2 conrod, which had lovely helical gouging in it!) On another occasion, I found a timing chain clip and roller on it.

That magnet looks strong enough to work through the thickness of the sump. You could mount it on a bracket against the outside of the sump near the drain plug. At oil change time you would unfix the magnet and slide it towards the open drain plug and the sludge/tell-tale bits might follow it and come out of the plug hole. However, I would recommend a conventional magnet.

Bob Schapel
R L Schapel

I have a question on these magnetic drain plugs for Tom Lange.
Is the one you provide for the rear axle BS, or UN thread, or can you supply either?

John
J Scragg

This thread was discussed between 08/05/2020 and 10/05/2020

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