Phoenix from the flames - Porsche Boxster with an Audi 2.7T

[Escy]

I decided I wanted to go back to a dyno to get the methanol tuned. Indigo GT were booked up for a month so I got it booked into Got Boost in Bridgend for Friday the 23rd.

It was the weekend before and I decided I wanted to make some changes to my inlet pipes, I was thinking about why it could be a bit short on power, someone suggested the flexible pipe I was using for my intakes is no good, although it's got a spring inside they said they've seen the inner lining close up previously. I've never been that happy with my air filter location so decided I'd change things before I go back. This is how they were

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When I got under the car I had an unwelcome but familiar sign, the sump pan was leaking again.

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Had another go at sealing it, this time I changed my technique, left it longer before fitting it hand tight and torqued it up after an hour.

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This is the stuff I bought to change my intake around. Was going to change the filters but couldn't find anything I thought would fit so stuck with these. Those barbs are quite cool, you can fit them into silicone pipes and they compress and seal themselves. I used them for the crankcase breather.

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This is what I've come up with. Mounted a little higher than before and protected by the undertray from rain. Still not ideal, won't be wading through floods any time soon. Got these sorted out and back together by 12pm Thursday night. Dyno booked for Friday 9am. So cutting it fine.

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Went out to get fuel that night, put my foot down and felt and heard a boost leak. Got back to discover the pipe that goes on the throttle body had split, common issue apparently, on the RS4 they use an aluminium version of it. I went down to my friends house who owns a B5 S4 first thing in the morning to borrow his. Turns out his had also split (smaller than mine) so I had the admit defeat and cancel last minute. Quite frustrating.

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Picked up 2 of them from TPS this morning (Saturday). Only £26 each which I thought was good.

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Went out for a test drive and had a boost pipe pop off as soon as I came on boost. Limped it back and saw this. The oil wasn't what I expected to see. There is no crankcase breather on that side so it's coming from one place only. The turbo has died. It's got play side to side and in and out. I'd actually had a feel of it 5 miles ago when I was fitting the inlet pipes and it was fine, the boost pipe coming off seems to be what's killed it.

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This update comes full circle, when I went under it the sump is leaking again.

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It's safe to say I've got the hump at the moment, looking like a summer under it and not driving it again. The sump issue is strange, was fine before I had to replace the oil pan. Had loads of goes, used a press metal gasket, various silicones and it just won't seal. It was sealed fine this last time, when the car sees boost it started leaking. Thinking maybe the crankcase breather has an issue or there is too much blow-by or something. Going to compression test the engine. It was a little down on the expected power. I was noticing a little puff of smoke out the oil cap at the rev top of the rev range last time it was on the dyno. This does seem fairly normal when I watch dyno videos?!

I'm not sure what to do with the turbos. There's a few options, easiest and cheapest is to replace the core. Can get Chinese ones for £60 or get a pair of genuine Borg Warner for £250 each and fit them in my housings. Although everyone seems to do it, I'm starting to think running a set of turbos flat out might not be the best idea for reliability regardless of Chinese/Genuine, wondering if a BW one would have gone the same way then the boost pipe popped off? For £1250-£1500 I can get some hybrids with a bit more headroom (which might lead me into spending a load of money on other supporting upgrades).

[mwstewart]

I would stick with standard turbos for now. Use genuine parts. Get to a point where the existing package is reliable before stressing components with more power.

Is there anything on the oil supply or drain side of things that may have contributed to early failure?

I don't like smooth hose connections for boost hoses - can you have a bead TIG welded on the end? Make sure it is sanded smooth afterwards to prevent damaging the hose.

What sealer are you using on the sump? I use Tiger Seal, and once set it bonds so well that it would be possible to omit the bolts entirely - don't try it though...

[Gtom]

Are you still using k03s turbos?

If so, try Beach Buggy Turbos if you go down the replacement route. They do hybrid turbos at reasonable prices and they seem to get raving reviews.

[Escy]

mwstewart said:

I would stick with standard turbos for now. Use genuine parts. Get to a point where the existing package is reliable before stressing components with more power.

Is there anything on the oil supply or drain side of things that may have contributed to early failure?

I don't like smooth hose connections for boost hoses - can you have a bead TIG welded on the end? Make sure it is sanded smooth afterwards to prevent damaging the hose.

What sealer are you using on the sump? I use Tiger Seal, and once set it bonds so well that it would be possible to omit the bolts entirely - don't try it though...

I'm going to remove the oil drains for both turbos and run the engine to compare oil flow, wouldn't want to kill a replacement.

I've been using 3 different silicones, one was the copper colour Loctite, one a generic one I got from Euro Car Parts and the other a black Loctite. All apparently suitable for sumps. Because the leak coincided with the first time the car saw boost I'm going to make sure my breather system is working correctly. I hadn't thought of Tiger Seal but that stuff is amazing, would need an axe if I ever wanted to remove it!

Getting lips welded onto the charge coolers is a good idea but I don't know anyone that can tig and the system is a pain in the arse to fill back up if I drain it. This is the first time that pipe has come off (had others come off before) so it's not a long standing issue. What I could do is replace the silicone bends with stainless steel pipes so I've just got little silicone joiners and then make physical brackets to hold it all together. It's all rigidly mounted to the engine so I don't need the flexibility of the silicone hoses.

Your suggestion for the turbos is the sensible one however I've got form for doing stupid things. I think I'm going to pull the engine, it's not a simple job to replace the turbos so I kind of feel like if I'm going to the effort and the expense anyway I should upgrade. Haven't made an decisions either way yet.

[Escy]

Gtom said:

Are you still using k03s turbos?

If so, try Beach Buggy Turbos if you go down the replacement route. They do hybrid turbos at reasonable prices and they seem to get raving reviews.

It's on K04's at the moment. I've sent them a message to see what they've got.

[Escy]

I compression tested the engine, good news is all the cylinders are within 5 psi of each other. The odd bit was they were 210-215psi and the engine should be 190psi max.

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I bought a bore scope recently so thought I'd have a look inside. I'd pulled the fuel pump fuse and the engine hadn't run for a day, there is what looks like oil in every cylinder. This one probably being the worst.

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I'm thinking it's probably valve stem seals leaking which will explain the higher compression and could explain why the engine keeps springing oil leaks if the crankcase is being over pressurised. The last time I drained the oil I found a bit of plastic in the sump.

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With all that considered and the fact I need to change turbos, the engine is coming out. I'm thinking I'll take the opportunity to do a few upgrades. I've got a set of forged rods in the garage from the engine that was in the fire. As the heads are coming off and I want to replace the upper section of the sump (it's got a helicoil repair on it) it'd be daft not to put them in. As for the heads, I'm thinking I'll fit some N/A heads which have larger ports, they are very similar to the RS4 cylinder heads. As it turns out there was a bloke selling a 2.4 engine with all ancillaries and the gearbox around the corner from me for £80. Talk about cheap!

I went to collect the engine, told him to take the gearbox off, didn't want that. The Allroad swallowed it up no problem.

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I haven't got space for it and getting it into the garage was more hassle than it's worth (moving it up hill on my Tod) so I lifted it up with my engine hoist and drove the car forward so it was free. Then I set about pulling the heads off it on the road. Yes, I'm sure my neighbours love me! I started at 6pm so it was a bit of a race agaisnt time.


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Finally got the heads off about half hour before it went dark. Had a bit of a panic as I couldn't find the special tool for the head bolts but it was hiding in plain sight. The heads look in really good nick, it's done the same mileage as my 2.7t if I can trust what they said, it's got none of the carbon build up my engine has. I guess the turbo engine is harder on the oil with scheduled services being the same on both engines. I noticed the same thing the last time I pulled some 2.4 heads off. Bargain for £80.

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I'm not 100% sure if I'll use the heads yet, I need to make a decision on the turbos first, if I stay the same size I probably won't. If I can dig deep and get some bigger turbos I will.

[Pupbelly]

Cracking result on the £80 lump!! I'm sure the neighbours are watching with great anticipation (from behind their net curtains )

[StreetDragster]

Escy said:

Getting lips welded onto the charge coolers is a good idea but I don't know anyone that can tig and the system is a pain in the arse to fill back up if I drain it. This is the first time that pipe has come off (had others come off before) so it's not a long standing issue. What I could do is replace the silicone bends with stainless steel pipes so I've just got little silicone joiners and then make physical brackets to hold it all together. It's all rigidly mounted to the engine so I don't need the flexibility of the silicone hoses.

On a previous project, I have seen people drill and place rivets in the ends of straight pipes where they don't have access to a welder/pipe beader, the silicone pipe them goes over the top and the head of the rivet forms a backstop for the hose clip. If using pop rivets though, make sure there is nothing to fall out into the pipe.

[Escy]

I'd previously considered a boost pipe popping off as a mild inconvenience, especially as my ecu doesn't use an air flow meter, just drive it at low throttle back home.

Now it looks like the cause of damaging a turbo I'm definitely going to put more thought into my charge pipe connections, especially if I'm running more expensive turbos next time.

[B'stard Child]

Borrowed from elsewhere

teaboy said:

Originally the stub of pipe on the outside of the tank on the feed up to the swirl pot was a separate piece with the main pipe swaged for the stub to slip inside it.




I don't have anything to swage the pipe so I can slip the inlet stub into it so I will have to leave the pipe in one piece and just form a bead on the end of it.

The trouble with that plan is that I don't have anything to form beads on pipes either!

After a bit of contemplation, and some tea, I came up with a plan.

I found these.




Which I made into this.




Which should be a die to fit this.




When welded to a set of Lidl moldy grips with a few other tweeks.




Works like this.




First test piece was a bit lumpy and too close to the end.




But a bit of fine tuning of the tool means they now turn out like this.




It isn't as lop sided as it looks in the pic.

I can live with that!

Might be useful for you to copy

[Gtom]

I came here to post this I saw years back, very Heath Robinson but if it works it works.

[rdodger]

Bead rollers are cheaper than turbos

https://www.stakesys.co.uk/bead-formers-jennys/man...

[Escy]

Thanks for the suggestions. I'll definately make some changes to stop it happening again.

[mwstewart]

Nice DIY bead tools. The outlet in question is ~2.5mm wall cast aluminium, so unfortunately cannot be swaged but the stainless boost pipes should work.

I think the N/A heads should be used if you are going to the trouble of a rebuild.

[Escy]

Yeah, welding a lip on like you said is the best way for the charge coolers. I've taken them off so will see if I can find someone to weld them.

[FNG]

B'stard Child said:

Might be useful for you to copy

He's not finally finished that tank has he? (I'm expecting not)

I need to go and catch up

[FNG]

Escy said:

I'd previously considered a boost pipe popping off as a mild inconvenience, especially as my ecu doesn't use an air flow meter, just drive it at low throttle back home.

Now it looks like the cause of damaging a turbo I'm definitely going to put more thought into my charge pipe connections, especially if I'm running more expensive turbos next time.

Commiserations - I thought the same til I had a hose pop off my 200sx due to a failed clip, and it overspeeded the turbo.

Awesome car, though. I've thought about a 2.7TT conversion into a 944 a few times but to be honest with the work you've had to do, including integrating the ECUs and playing with CAN signals, I'm glad I didn't as it's beyond me.

Hats off for pulling such a fabulous car together.

[B'stard Child]

FNG said:

B'stard Child said:

Might be useful for you to copy

He's not finally finished that tank has he? (I'm expecting not)

I need to go and catch up

You are quite correct he hasn't finished the oil tank

If he stops trying to chop his fingers off he'd probably make more progress

[kev b]

Top persistence, I would have given up by now, nearly reached the end of my tether just stopping the cam covers leaking on a 2.7T

Have you tried using Elring Dirko sealant on your sump?

It’s apparently what VAG use at the factory, worth a shot at £12 on Ebay.

Enough to do 6 sumps so should last you a couple of weeks.

[tonyvid]