Bearings Question

Hi everyone

Quick question. Do people typically replace bearings on these as a preventative measure or is it best to leave well enough alone? Car has 155,000km on it and is a 91 VR4 GTO.

Also what sources are people using for MK1 TT oil pumps? These seem like a very important part for the survival of these cars so its worth a discussion on it. I see some availability but for extortionate prices. Ive even seen people selling 2nd hand ones!


Which bearings are you referring to Mike?

Pretty sure oil pumps are available from a good motor factors last time I enquired.

Sorry @Joe90 I should have been more specific! The big end bearings is what I was referring to. All I seem to see online is rod knock and spun bearings. I would be very interested on your thoughts on preventative maintenance for this. Should I be replacing bearings
at this point? My car is running sweet now and I would like to keep it that way.

Is there a test/inspection that would be sufficient?

Also, it would be great to know what oil pumps you use as I would like to change mine.

Thanks again

I am sure that this question will start a big debate and I can only give my view based on my own experience. The oil pump is a centrifugal pump and should last the life of the car if you have done regular oil changes from day one. Every one that I have rebuilt was down to the owner not doing proper maintenance and having oil that looked like tar with metal filings in it.
The life of the bearings is also down to regular oil changes and if it is a turbo, how hard you drive the car. If you are flat out between every light, you should expect more component breakdowns but a sensible driver will get twice the life.
There are a number of owners on here with more than 250k miles who have never had any problems and I personally have never had to change either of these items in my cars.
Look after your car and it will look after you.
That’s my view anyway.


Thanks Joe, I appreciate your opinion on it. I think where it gets more complicated is very few have a detailed history on their cars so its hard to know about oil changes etc. I thought Mitsubishi recommend a new oil pump at the 120km mark but I may be wrong.

Can I ask what oil you prefer in your TT car?

I have always used valvoline but I am sure that there are many other good oils. The main thing is to change it on a regular basis.
I haven’t heard of the recommendation to change the oil pump before. Do you know if this is factual or good old Facebook rumours?
Looking inside the rocker cover will give you an idea of how well the engine has been maintained.


I use Havoline 10w40 and have used it since I got my GTO 6 years ago and the engine runs extremely good… The only thing I can recommend is that you never ever put too thin oil into your engine as it will cause havoc on many gaskets as they simply cannot keep that thin liquid thight… I also change my oil every 4000 km or 2 times yearly and that is a strict rule… If you maintain old engines with oil changes and filter and just look at the oil when you drain it, then you can prevent a whole lot of issues.


Thanks @Joe90 , it is most likely from the forums, FB etc but almost without exception everyone suggests oil pump at 120km.

Do you use 10w 50, 10w40 , 5w40 or one of the many others. I know the manual gives guidance but I’m not sure 30yrs later if there are better options.

To add to this - I use 10w40 oil as in some of the service records for my car this is what Mitsubishi used.


I use 10/40.
I trust mitsubishi over Facebook and forum guesses. So far they have been right.


I’m with you on that Joe about oil pumps. I dont know what the thing is behind gus wanting to change them out. I had to change mine - NA manual - as I caused exterior damage to it and only managed to change with a secondhand one from an NA auto. Works perfectly but has a leak from the side (probably not seating gasket properly or something) so I’ve started pulling everything apart again. I honestly wouldnt recommend changing an oil pump unless absolutely necessary. It really is a pain in the butt job. Especially when you’re not a mechanic.

Hello Mike TTGTO, only the main bearings can be changed out without the need of a complete engine disassembly. I would do it if this was my ride, if, there is no evidence to show that there was a major engine rebuild or just the main bearings were replaced, regardless of how many miles are seen on the odometer. But then again you don’t have to do anything and just keep a regular oil change schedule and do not red line the engine and hopefully you shall be fine, but the downside is, you do not know for sure if these main bearings were replaced nor do you know for sure what they actually look like and this can be seen when you remove the gridle and examine the lower bearings. If they have signs of excessive wear then yes they need to be replaced. There should be information on the net how to determine bearing wear. If new bearings are installed then you will need to do a oil clearance check. The downside i mentioned above is having a spun bearing which generally it would be a main bearing first to go, if it is a rod bearing that goes out then there shall be catastrophic damage. A spun main bearing will inevitably damage the journal and if that happens it shall be time for a complete engine rebuild. I always say “better safe then sorry”

Always consult the Mitsubishi shop manual for service and repair, and like Joe said, not to pay too much attention to what others say…I have done a complete rebuild on my stock engine and keeping it that way with very few upgrades for better oil flow, intake and exhaust flow, coolant flow, fuel flow and other small details to keep her in the greatest condition ever and all has been done using manuals and a few tit bits from highly professional engine builders. There is a guy on youtube that has a channel called EE ( Engineering Explained) with each of his videos has over a million views, very good and logical information for automotive enthusiasts, he also has discussed oil requirements for combustion engines. If you are running a stock engine with stock internals go with what oil Mitsubishi recommends including spark plugs, I have seen and heard a lot of people use the wrong spark plugs for their stock engines and inevitably issues start to buildup. But if you have done serious modifications to your stock engine with aftermarket internals and other nice stuff, then it is up to you to use whatever oil you think is good for your build. On the discussion of oil pumps, I have not heard or read in the shop manual that it is recommended to change out the pump at 74k miles ( I could be wrong ). Obviously it is hard to see oil flow in an engine but oil pressure is one way of knowing you have the required circulation but ( then again the sensor good be wrong or you have serious wear and tare on the gears that are made of powdered metal and can wear fast using the wrong oil viscosity or mechanical problems like a out of round crank, bad bearings and perhaps other stuff, considering you can just imagine how fast that gear spins since it is crank driven) and I have seen that happen, obviously your car will overheat if you have poor oil flow and pressure and then if you do not catch it in time you will have catastrophic damage to rotating parts. In my build I have added an external oil pressure gauge, however, the safest way to go about this is to change your oil and oil filter more often then required, by doing that you are basically flushing out all the contaminants and debris from within and then you get to see if there are any metal shavings in the pan, hopefully not. Also a very expensive oil filter is the way to go There is money to be spent to keep these obsolete hard to find classic JDM cars in tip top condition, sad to see them becoming an endangered species due to neglect ( that was a joke), sorry this message got so long I was just bored!!


Just to clarify my earlier thread about using the word ‘only’, which is incorrect, the rod bearings can also be changed with the crankshaft installed.

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