HELP - Aftermarket DPF to Exhaust Gaskets!!!

[Stophen]

Hi All,

Last year I fitted a new aftermarket DPF to my Ford Focus Mk2 1.6TDCi with the help of this forum.

Since then the DPF has been great but my wife has complained of exhaust fumes when the car is stationary / idling.

I decided to perform the blowing vacuum / soapy water test which showed that there was a leak between the new DPF and the original flexible tale pipe. I rang my local Ford dealer and picked up a new gasket hoping it would solve the problem. Unfortunately the same thing happened again leading me to the decision that the gasket associated with my registration is either incorrect or incompatible with the aftermarket DPF.

I have attached pictures which show the issue:

I also have some small exhaust leakage between the DPF and the turbo where the bracket joins together:

Does anybody have any suggestions of types of gaskets that would fit to the flexible exhaust pipe and a solution for the small leak between the bracket (i.e. high temperature metallic paste)?

Many thanks in advance!!!

Stophen.

[nicam49]

Well, exhaust centres use a paste.*.. now that you've got 2 sealing gaskets can you use the 2 together?                             *also, on Wheeler Dealers Ed always uses a sealing paste too when joining exhaust sections together.. and it's not that horrible black gun gum stuff either.                                         OK, I've just used Google, and there's stuff called exhaust assembly paste out there, ECP and Halfords sell it. 

[Stophen]

Hi @nicam49,

Thanks for your comments, when you say; 

15 minutes ago, nicam49 said:

now that you've got 2 sealing gaskets can you use the 2 together

What do you mean? 

Also the paste sounds like a good idea, could I use that on both joints?

Thanks, Stophen.

[TomsFocus]

Aftermarket DPFs are just made badly, hence the poor fitting.  2 gaskets together might be thick enough to seal the lower joint.

If you do use any paste, only use it on the lower joint.  Don't use it before the cat.  

[Stophen]

Thanks @TomsFocus,

I think I will try a couple of exhaust specialists where I am to see if they have other gaskets / ideas...

Could I use something like exhaust repair tape with the join from the turbo to the DPF and then clamp it altogether or is that asking for trouble?

Cheers, Stephen.

[TomsFocus]

It's not really the gasket that's the issue, there is only one shape for these.  The angles are wrong on the DPF so it doesn't sit between the turbo and mid-pipe perfectly. Meaning the two faces there don't sit flush.  

Personally I'd give up with the lower one and shift the DPF around until you can seat the turbo end better.  That's where the gasses will be getting into the cabin from, and being pre-cat, they're as toxic as you can get!

Exhaust tape is pretty useless lol, and I can't see it taking the huge temperatures that come through there during regen!  The V-band clamp should be good enough, was it a new one or still original?  (This one time, at band clamp...  )

Also worth noting it's not unusual for an occasional leak there as standard.  When the DPF is getting full of soot and causing back pressure, that's the weak point for a little gas & soot leakage.  Should stop leaking again after regen though.

[Stophen]

Thanks @TomsFocus, your explanations are always spot on!

I fitted a new v band clamp hoping it would resolve the issue. I tightened it as far as it would go and It did pretty well but the gas still escapes between the two joining sections of the clamp. I just need something to fill that gap..?

Would adding some kind of exhaust sealant on the inside section of the gasket help create a better seal?

Cheers, Stophen.

[TomsFocus]

12 hours ago, Stophen said:

Thanks @TomsFocus, your explanations are always spot on!

I fitted a new v band clamp hoping it would resolve the issue. I tightened it as far as it would go and It did pretty well but the gas still escapes between the two joining sections of the clamp. I just need something to fill that gap..?

Would adding some kind of exhaust sealant on the inside section of the gasket help create a better seal?

Cheers, Stophen.

Hmm, it's just poor manufacture tolerances again.  The DPF isn't meeting the turbo perfectly if there's a continuous leak from the gap in the V-band.  The clamp is just there to hold them together, not do any sealing.  The only fix is going to be a bodge, but I have a feeling it'll blow anything you try to put there.  This is the reality of aftermarket parts unfortunately. 

I definitely wouldn't use any liquid or paste type sealant around there, but maybe a thin metal V shape ring around the outside would work.  Possibly even tinfoil?  Just thinking aloud, I've never done it!

Regarding the bottom joint, yes a bit of paste or sealant on the gasket would be fine.  Do both sides as the current gasket has already been crushed once so wouldn't seal properly again anyway.

[nicam49]

I've deleted my original reply as Tom said it all, but tinfoil will just burn through...* Maybe gungum silencer repair tape wrapped round the gasket used in conjunction with gungum putty is a possibility.... 🤔                         *major bodge ahead alert*

[bashbarnard]

The bit between the turbo and the dpf you'll never get to seal. Not in a month of Sundays. I've fitted hundreds of these now and they always leak a little. Do not put anything before the dpf exahsut paste wise. I've also recently started not using exhaust paste and using high temperature silicone after a few techs had switched. Honest to god I won't be going back. Find some high temp silicone, bit on each side of gasket. Let it go off, it'll never blow again. Marvelous stuff compared to exhaust paste. I won't ever go back.

Sent from my SM-A505FN using Tapatalk

[Stophen]

Thanks @nicam49, I was thinking it would need to be something fairly industrial to cope with the temperature.

I think I'll pop to an exhaust specialist tomorrow and see if they have any tricks up their sleeves, I'm sure they must have seen these kind of issues before!

Cheers, Stophen.

[Stophen]

Thanks @bashbarnard for the tip. I'll bare it in mind if the exhaust specialist can't suggest anything else...

The leak is only occurring between the two closing points (where the v clamp doesn't go). If there was something out there that could bridge the gap or clamp the whole thing then I would be in business!

My main concern is my wife, she has a nose like a blood hound and she will use this as another reason for me to sell the car... And I probably should but i'm too tight 😂.

[Stophen]

Thanks @TomsFocus.

It sounds like sealant is the way to go. Just to be clear, are you saying to use both the original gasket and the new one i've just purchased and sandwich them altogether?

I'll have a wee internet search and see if there is anything out there that can withstand the temperatures to sit between the DPF & turbo.

Cheers, Stophen.

 

[Stophen]

Just wondering if something like this might work to sandwich between the DPF & turbo:

https://www.holtsauto.com/holts/products/easy-fit-bandage/ (with a little customisation)..?

[TomsFocus]

1 hour ago, Stophen said:

Thanks @TomsFocus.

It sounds like sealant is the way to go. Just to be clear, are you saying to use both the original gasket and the new one i've just purchased and sandwich them altogether?

I'll have a wee internet search and see if there is anything out there that can withstand the temperatures to sit between the DPF & turbo.

Cheers, Stophen.

 

Either sealant or double gasket, I wouldn't do both together, double gasket is just a tight mans bodge really lol.  Sealant each side of a single gasket is the better option as Bash said!

[Stophen]

26 minutes ago, TomsFocus said:

Sealant each side of a single gasket is the better option as Bash said!

Thanks Tom, any thoughts on the link I posted or am I just wasting my time in the search for perfection?

Oh, would you recommend any brand or product of sealant? 

[nicam49]

I think you need to respect your wife's nose! What it's detecting could be a warning of that aromaless killer carbon monoxide....have a look at the Holts gungum range... I was thinking more of a foil bandage + gungum paste that you can wrap around the gasket to bulk it out than that pipe repair thing you've seen.

[TomsFocus]

2 minutes ago, Stophen said:

Thanks Tom, any thoughts on the link I posted or am I just wasting my time in the search for perfection?

Oh, would you recommend any brand or product of sealant? 

I spend most of my life looking for perfection so can't really answer that question...   It depends how much leakage you're getting...if it's enough to smell in the cabin under normal conditions then I'd suggest you can improve on that...but you won't ever seal it 100%.  

I can't see that bandage being of much use, and it's expensive compared to a spare piece of metal...just wondering if there's any sort of grocery packaging that might work...  

Can't advise on the high temp silicone sealant I'm afraid, I've only used the old paste, not had to fix an leak like that for nearly 5 years myself.  

[Stophen]

Thanks @TomsFocus & @nicam49,

I think I will try the; https://www.halfords.com/tools/garage-equipment/head-gasket-and-exhaust-repairs/holts-firegum-150g-741520.html for the exhaust sealant & the; https://www.halfords.com/tools/garage-equipment/head-gasket-and-exhaust-repairs/holts-gun-gum-exhaust-repair-bandage-716043.html for the DPF to turbo fitting.

I'll pack out connection like you suggest and see what happens. I'm guessing if it goes wrong and the bandage gets sucked into the DPF it will just get burned up during regen..?

[F0CUE]

That holts paste is garbage it works for a while then it all cracks and breaks off the bandage is probably just as bad. I would suggest This for the gasket and This great lifesaver for the other pipe. 

[Stophen]

Hi @F0CUE,

Thanks for the suggestion. 

The silicon looks good. Do you think the heat wrap would be flexible enough to deal with the curves of the turbo coupling?

Cheers, Stophen.

[F0CUE]

Yes it's like a cloth like material and once wet it can be positioned on to it then the heat does the work. 

 

[Stophen]

Thanks @F0CUE,

From the YouTube videos it looks good and has a high temperature threshold.

Would you recommend wrapping the tape over the DPF and turbo connection when it’s all connected up and then clamping it down to keep it in place, or leaving it to cure before tightening the V clamp?

Cheers, Stophen.

[F0CUE]

I would think the clamp would maybe damage it when not cured and you would be back to square one once upto temparture the wrap hardens over time. 

[Stophen]

Ok @F0CUE, I’ll give it a go wrapping it around the connection, wait for it to cure and then attach the clamp, hopefully the clamp won’t break the cured wrap..?