MR2 Roadster Owners Club

The Workshop => Maintenance, Problems & Troubleshooting => Topic started by: Nvy on July 28, 2019, 17:28

Title: Subframe seeking for an advice
Post by: Nvy on July 28, 2019, 17:28
So while I was removing my TTE I noticed that the subframe has some surface rust. Any advice of what to do? Should I remove it and fully inspect it or I can do it while on the car? Also any advice if I should just go ahead and get a new one and replace it?

It seems like nothing major but I read that these rust from inside out so im not sure. No holes or anything is present. I bought some Hammerite to threat it but decided to ask first on here :)
Title: Re: Subframe seeking for an advice
Post by: Ardent on July 28, 2019, 18:00
Yes. They go from the inside out.
The main area to focus is where the exhaust passes under. Give it a reasonable poke in that area.

If solid. Go with the hammerite on the outside and some cavity protection on the inside. Can be done institu, just awkward.
I like bilt hamber dynax a50.
Title: Re: Subframe seeking for an advice
Post by: 1979scotte on July 28, 2019, 18:07
I do agree with Jason above however if your 2 is forever like mine I would look at getting a new one from Toyota before they become unobtainable.
Title: Re: Subframe seeking for an advice
Post by: Carolyn on July 28, 2019, 18:19
Yes, as Ardent points out, they do rust from the inside at the hottest point.  I did quite a bit if research into this.  It turned out our subframes tend to rust a lot faster than even Canadian ones!

The reason appears to be that winter road salt and water get in via the open holes at the four top corners.  The red salt used on our roads has a high potash content (white salt tends to be used in North America).  The potash makes for a very corrosive electrolyte that sits at the low point inside the sub-frame.  Heating by the exhaust speeds up the chemical action.  Result - holes!

My answer to this is to take out the runner bungs and wash the inside out with water to get rid of salt build-up, then drive around with the bungs out for a while, to dry it out.

Then I use engine sealant to close up the holes at the top corners, so more salt and water can't get in.  Then replace all bungs except one.  Pour in a good dose of waxyoil or other such rust preventer.  Enough to be able to slosh around while you drive and give it all a good coating.  Then put the last bung in.  No water, no salt, no fresh air = no rust!

Addendum:  If you look carefully, above the suspension mounting points in the middle bottom of the sub-frame, there are two very small holes.  They are intended as drain holes (they don't work all that well as they tend to block up).  Tape them over before you pour your rust preventer in, or it'll slowly dribble all over the floor.
Title: Re: Subframe seeking for an advice
Post by: litr0m on July 28, 2019, 18:20
Mine was crusty as hell so o decided to by a new one. 350gbp and now Everything is solid for at least the next 7 to 15 years.

Also did new bolts washer etc.
Title: Re: Subframe seeking for an advice
Post by: Ardent on July 28, 2019, 18:59
I went for a new one.
But then mine resembled swiss cheese.

Got to be a limited number of new ones now. Good time to get one. Needed right now or not. Not like you would lose out if you bought one.
Title: Re: Subframe seeking for an advice
Post by: Nvy on July 28, 2019, 19:16
Thanks guys, ill look into buying new one but will keep using the one thats on the car. I have the hammerite and will look into the other stuff. I decided to work on the car myself so i have to learn how to jack up the car and put it on stands first and then will examine the whole thing. I know the jack up point where the mount is but not where to place the stands. Ill have to improvise how to paint it too but thats in future.

The car was never driven in the winter and salt at least thats what the previous owner told me. He had it for 11 years, wasnt great tinkerer but the car is fine.
Title: Re: Subframe seeking for an advice
Post by: shnazzle on July 28, 2019, 19:51
Mine's in a similar condition. What do we think of some high quality heat reflective material to block the cat heat and decrease the effect of that heat on the subframe?
Title: Re: Subframe seeking for an advice
Post by: Carolyn on July 29, 2019, 08:16
Quote from: shnazzle on July 28, 2019, 19:51Mine's in a similar condition. What do we think of some high quality heat reflective material to block the cat heat and decrease the effect of that heat on the subframe?

Can't hurt.  The standard cat has massive heat shielding on it, but the problem persists.  Doubtless it would be worse without.  I tend to wrap the aftermarket cats to try and get some protection.

Not driving in winter conditions obviously helps.  Especially avoiding days when salt and slush are about. If your 2 is your daily-driver/commuter, you don't have that option.  Occasional pressure washing the underside with 'Salgon' (salt remover) will help protect all of the exposed underside.

Even if you are fitting a new replacement sub-frame, I would recommend giving it the full protective treatment inside and out before fitting. No reason why it should not last indefinitely if that's done.
Title: Re: Subframe seeking for an advice
Post by: paulj on July 29, 2019, 20:09
As for paint, I was thinking a coat of normal hammerite to stop rusting and then a top coat of hammerite barbeque paint to provide a heat resistant finish.  I am planning to give mine a coat of paint this winter.
Title: Re: Subframe seeking for an advice
Post by: Ardent on July 29, 2019, 21:52
I'm on smoothright and no issues near the hot spot.
Title: Re: Subframe seeking for an advice
Post by: Nvy on August 5, 2019, 08:09
After a detailed look on the subrame I tried to press on all places where there is rust and it seems solid. There is a small whole but its not rusted, looks like somebody did it on purpose. The insides of the subframe look good, no rust or anything, i could look through the bungs. Other than that there is rust in lots of places, its just surface rust but I guess it will turn into restoration project. Id need to take the subframe off and threat it the way you guys described.
Also the tranny is covered with oil which is not good of course so this will need sorting too.

Couple of questions:
1. Can I threat the whole engine bay with Hammerite? I found Hammerite in cans and I could paint the whole engine bay with it.
2. There is a thermo reflective golden heat tape, should I cover anything in the engine bay with it? I know it is not needed but is it a good thing to do so?
3. What skill level is required to drop the engine out and to tuck it back in again? Id like to sort the whole engine bay and also clutch, TB & Intake manifold gaskets.
Title: Re: Subframe seeking for an advice
Post by: jonbill on August 5, 2019, 09:05
For me, getting the engine in or out is a weekends work. Others are quicker I'm sure, but I certainly wouldn't do it just to paint the engine bay.
Title: Re: Subframe seeking for an advice
Post by: Carolyn on August 5, 2019, 09:26
Quote from: jonbill on August  5, 2019, 09:05For me, getting the engine in or out is a weekends work. Others are quicker I'm sure, but I certainly wouldn't do it just to paint the engine bay.

Worth doing if it also needs a clutch, though?  Not a job for a beginner or for someone with limited tools, I think you'd agree?
Title: Re: Subframe seeking for an advice
Post by: jonbill on August 5, 2019, 11:12
Quote from: Carolyn on August  5, 2019, 09:26
Quote from: jonbill on August  5, 2019, 09:05For me, getting the engine in or out is a weekends work. Others are quicker I'm sure, but I certainly wouldn't do it just to paint the engine bay.

Worth doing if it also needs a clutch, though?  Not a job for a beginner or for someone with limited tools, I think you'd agree?
Agree. You have to have time, space and tools. Not something you'd do casually without a lot of experience.
Title: Re: Subframe seeking for an advice
Post by: Call the midlife! on August 5, 2019, 11:47
Quote from: jonbill on August  5, 2019, 11:12
Quote from: Carolyn on August  5, 2019, 09:26
Quote from: jonbill on August  5, 2019, 09:05For me, getting the engine in or out is a weekends work. Others are quicker I'm sure, but I certainly wouldn't do it just to paint the engine bay.

Worth doing if it also needs a clutch, though?  Not a job for a beginner or for someone with limited tools, I think you'd agree?

Agree. You have to have time, space and tools. Not something you'd do casually without a lot of experience.

Speaking from similar experience I'd agree with the above, also adding the surprise at the amount of space you need to properly store the component parts if you decide to start stripping them off.

If you're dropping the engine and drivetrain just to make painting the engine bay easier you're running a lot of risks of damaging important  parts just to make others look pretty.
Having said that I gave mine a good tarting up while it was out.👍🏻
There's a bloke on the Facebook page recently sprayed everything in the engine bay with silver paint to improve the appearance, hoses and pipes and everything. You could always try that approach...🤓
Title: Re: Subframe seeking for an advice
Post by: Nvy on August 5, 2019, 11:53
Well dropping the engine is the last thing I want to do but I want to fight the rust. Last time when the go to guys worked on the car I spent 1/3 of the car price for suspension refresh. Just for the work, no parts from their side. So ideally I know that I cant get it done in 10 hours but Id like to save some cash. If they do it for me it will be more than 1k pounds.

Last time suspension refresh was 700 quids - that includes all bushes, coilovers and brakes. Its a bit steep for me and they are charging me a lot because they havent worked on such car.