VR6 head work?

[Robbo149 0]

Hi all VR6 experts, I'm posting this as I'm trying to tie together a few minor issues to see if any are related & what to do about them. I have a couple of probs with my 100k VR which in general seems to run pretty well - The exhaust pops a lot when the engine's warmed up, the tailpipe is also pretty sooty, both of which I understand indicate overfuelling. The tappets are also pretty noisy all the time, even with fresh oil. So, first question: Could worn tappets cause overfuelling? It also seems to be using a lot of oil but there are no leaks & no smoke from the rear end, does this indicate worn valve stem oil seals? I'm planning on having the tappets replaced before too long & would like your opinions on whether it would be worthwhile going the whole hog & having a head rebuild (inc. tappets, valve stem oil seals, timing chains & tensioners etc) for peace of mind? Sorry it's such a long query, but I'm trying to decide what to do based on not much knowledge!

 

Oh btw, if it helps, a recent diagnostic check showed no fault codes at all.

 

Cheers all,

Robbo

[corradovr6sc 0]

Yes, worn seals means more oil useage. I'd get everything done including the head gasket if it's original. In for a penny, in for a pound! Someone like Stealth charge £1200 for this work unless you fancy having a go yourself!

[PhatVR6 0]

£1200!!!!!

 

I've just flowed and rebuild my head, it cost me about £150, including new exhaust valves...

[dr_mat 0]

So you did that yourself then...?

Would you do mine for £150? ;)

[Robbo149 0]

Yes I'll have mine done too, pleeeese Phat! I was anticipating a bill of around a grand for a complete head rebuild.

 

Robbo

[PhatVR6 0]

No chance! it took me all week!

 

Hmm, new exhaust valves, gas flowed and port matched, new stem seals, 268 cams......mmmmm

 

I fi get a spare head I might start doing them on an exchange basis. I might as well, plenty of companies out there charging the earth for them.

[Robbo149 0]

Keep us posted Phat, I'm sure there would be plenty of interest. I'd definitely fancy a nice new flowed & ported head with a pair of Schrick cams! What sort of wonga would you be looking at?

 

Robbo

[Kevin Bacon 5]

You can do it yourself with a dremel, a drill and the requisite attachments/grinding bits etc.

 

Need a spare head to work on though if you've only got one car.

[PhatVR6 0]

dremel, LOL! it'd do one head and it'd be burnt out.

 

you need a big air compressor and a die grinder, some tungsten carbide burrs, and lots of sanding drums.

 

I can get schrick cams for £500. springs for £100.

 

I'd have to get a price for new guides and getting them pressed in.

 

Valve seals are £2.84 each.

 

It took me a night to strip the head. the rest of the week of nights and a saturday after noon to flow it. then last night to put it all back together and lap the valves back in.

 

it's now back on the car, with Raceware head studs and amk4 12v head gasket (thinner for higher compression).

 

I'll get some pics up of the port work.

[Robbo149 0]

Nice 8) ! What sort of bhp/torque increase would a head job & cams give? does the ECU need remapping?

 

Anyone got any thoughts on the worn tappets = overfuelling question ?

 

 

Cheers,

Robbo

[PhatVR6 0]

I've never heard of the lifter "wearing out", the noise is more likely to be your cam chains. listen closer and tell us which end of the engine it's coming from. is it a ticking, or a cyclic clattering?

 

A mild port job and 268 cams should see up to 15BP, and no loss of midrange either. works mint with the schrick vgi, when it switches over at 4000rpm you can really feel the cams come in. I've yet to see if the porting and the waisted valves are goig to make much difference

[Robbo149 0]

Phat, it's a definite ticking noise & it's coming from the left of the engine (opposite end to cam chains). I just wondered if maybe worn tappets would cause the valves not to open & close as they should, hence overfuelling.

 

Cheers,

Robbo

[Kevin Bacon 5]

Tappets won't wear to that extent Robbo. I have the same tapping noise in my engine and I had the tappets replaced a few months ago. Shouldn't worry about it.

Not the injector rail ticking is it?

[PhatVR6 0]

yeah, could be a sticky lifter. sometimes an oil change will sort that.

 

have you checked your oil pressure?

[Robbo149 0]

Ok, things could be getting worse... I had a quick look at plug #1 today & it was oiled up! guess that explains where my oil's going! I didn't check the others as they're not so easy to get at, & I believe 1 & 6 are the ones to check anyway. I've never had any smoke coming out the back so does this make things better or worse?! Am I looking at a full head rebuild then?

 

Btw, the plugs that are in are Beru 4 electrode jobbies - are these OE or just cheapo replacements?

 

Please reassure me guys!

 

Robbo

[Kevin Bacon 5]

The plugs should be NGK or Bosch twin electrode jobbies, can't remember the numbers. Beru aren't bad plugs but they're not what VW specify.

 

I would check all of the plugs but yep 1 and 6 are the ones that oil up first, but that's usually down to premature bore ovalising.

[Robbo149 0]

Oh bugger!!!... that's not what I wanted to hear Kev. I don't really want to think about a knackered block! The car seems to run fine (apart from the oil consumption & a bit of exhaust popping), doesn't seem to be down on power & I never get any smoking... If it does turn out to be the bores & not the head should i just live with it? or is it going to go bye byes one day? Wouldn't leaking valve stem seals also cause oily plugs? Sorry so many questions but I'm getting desperate!

 

Cheers,

Robbo

[Kevin Bacon 5]

Sorry mate, not a nice thing to hear but very possible unfortunately!

 

When I was in the market for a Corrado, I initially wanted a G60 because all I heard about the VR was "timing chains" and "early bore wear". When speaking to Vince at Stealth once, he confirmed the latter. On the 2.9 engine, bores 1 and 6 ovalise before the other 4 do, for reasons unknown.

 

You might be lucky and just have knackered oil control rings and therefore the block is salvagable. I've never seen a cylinder head with worn guides just on 1 or two cylinders, but stranger things have happened!

 

Get compressiopn and leak-down tests done, only way to be sure without stripping the engine.

 

Oil doesn't burn as quick as petrol and therefore unburnt deposits stick to the valves, plugs and piston crowns.

 

K

[Robbo149 0]

Thanks for the swift responses Kev, you're a star! I'm sat here at work with my brain mulling over how many £K I'm gonna have to spend!

 

I don't know whether the other plugs are fouled, as I haven't had chance to check them yet, saw no.1 & my heart sank!

 

When you say compression & leakdown test, do you mean on the block? is this straightforward to get done without stripping the engine down? I hate the not knowing anything for certain!... you never know... maybe I'm being overly pessimistic!... (nah, my luck never works that way!!!)

 

Cheers,

Robbo

[Robbo149 0]

Me again!... got my car back last night from local garage after good check over. My friendly mechanic slapped my hysterical girlie face (not literally!), & told me to stop being so pessimistic! He pulled all the plugs & reckoned they weren't oily at all, just old & tired! So put some nice new NGKs in, told me compression seemed fine, checked the emissions - ok. Top end is a bit rattly (which I knew), probably tappets, so he put in some tappet cleaner to run through for a couple of hundred miles & see if it quietens down. I suspect I still could do with a head rebuild though, as It's using approx 1 litre of oil per 1000 miles. But at least the bottom end seems ok! (sigh of relief!). Oh, and my exhaust's knackered (joy!)

 

Cheers,

Robbo

[dr_mat 0]

Welcome to the world of VR ownership. Constant paranoia can overtake your life. I think I need a spare car just to prevent the hair loss..!!

:roll:

[Robbo149 0]

I think it's too late to prevent the hairloss for me! I know what you mean though, I was all set for bidding on a new engine on Ebay! It's spending too much time on this forum that does it :wink: , makes you think your car must have everything wrong with it that everyone elses has... let's call it "automotive hypochondria"

 

Robbo

[Storm 0]

Take a look at the price of a big boys toys cylinder head. £350 from memory + fitting. Get one with an oil cooler and that engine will be good for another 100k miles I think.

 

I have no affiliation with this outfit, but rang them and they really seemed to be good.

[Scott 0]

Funnily enough my garage (VW Specialists) told me same thing but the plugs were only 5k miles old!!!

 

I am still not convinced as it still using a little oil and still fouls up plug number one (number six doesnt foul up anymore :? )

 

At the moment the problem seems to come and go.... I'm tempted to take the drive down to Stealth and let Vince look at it... as the moment I am in two minds whether to sell it or not!!! :cry:

 

Scott

[Kevin Bacon 5]

as the moment I am in two minds whether to sell it or not!!! :cry:

 

But what can you get for 4 or 5 grand that is as charismatic, smooth and quick as the Corrado VR6?

 

Obviously there's a whole assortment of dull and reliable cars for that money, but anything performance orientated at that level will probably need more work than a couple of valve guides that yours needs.

 

K