Low compression on #2

[emax 0]

I put my car into Star to investigate some pinking with the Schrick and to refurbish the injectors and just got a call from them - it isn't looking good...

 

They have run a compression test on the engine and found that cylinder 2 is low on compression so the head is going to come off.

 

They're suspecting either the head gasket or piston rings.

 

I am surprised to find this as the car certainly doesn't feel down on power. How much does it cost for a head gasket replacement? £600ish? How much more for piston rings??

 

While the head is off, anything else I should get done at the same time?

 

This is a total disaster!!!

[Kevin Bacon 5]

It could also be worn valves and guides aswell as the aforementioned.

 

New rings entails a new short motor rebuild I'm afraid. Couple of grand plus fitting :cry:

 

Head rebuild, chains, gaskets etc around £1100 - £1300....

 

No 2 going down is unusual on the VR tho..... it's usually always 1 and 6 that bite the dust first....

 

Very bad news mate.... :(

[emax 0]

It would seem that if the rings are away it would be more cost-effective to get another block?

 

I can't believe this. The car wasn't exactly running badly! Also, I'm hoping it isn't the rings as I have never seen any smoke of any kind out the back when going back on the gas after running at high revs on the overrun. Fingers crossed it is the head gasket :roll:

[dr_mat 0]

*HOW* low compression?

And were you using any oil?

[emax 0]

I didn't get the compression results off him. As far as I remember, all other cylinders were high (at least the adjacent ones were).

 

Oil consumption would be in the order of 1.5 litres every 5000 miles so well within tolerance for the VR. No signs of cross-contamination in the oil.

 

Oh, and the car wasn't using much, if any water either.

 

Strange or what!

[Kevin Bacon 5]

Take it to Stealth and get a second opinion. No one knows the VR engine like he does..... depending on *how* they tested the compression, the results may not be accurate or conclusive anyway.

[emax 0]

I know what you're saying Kev but Stealth is quite some distance away from Scotland so it isn't really an option right now. Esp as my girlfriend is due to give birth tomorrow!

 

I've every confidence in Star too though so I'll let them do the necessary. I've got to go back there later on to give them my OEM wipers back as the lupo ones are going to fail the MOT. The driver's side one doesn't wipe a section of the screen just above the line of site for some strange reason.

[dr_mat 0]

Get them to show you the compression test results when you're there. As you say, Stealth is an AWFUL long way from you...

It's possible that the pinking has done the head gasket in, that's true. But if it's running well you'd have to ask if it's worth getting the work done right now...

[Roger Blassberg 0]

How many miles on the engine? Is it using a lot of oil?

 

Smoke after a long over-run usually means valve guides or valve stem oil seals. If the scraper rings are gone, you'll get

blue/grey smoke with power on.

 

I do hope it's either the head gasket, or maybe a leaking valve. If the compression pressure comes back up temporarily after a squirt of oil into the relevant cylinder, then it's probably rings/bore wear; if not it's most likely gasket or leaking valve

 

Just for information, a new head, complete from the block upwards and including cams and followers, was £750+vat exchange, from VAG this time last year. A lot of money, but a bargain for a total renewal. You save a lot of labour charges as well if you go in this direction, and you can forget top-end problems for years to come. My total bill, including the above, was £1600 incl.vat.

 

Best wishes

 

RB

[emax 0]

Thanks for the info.

 

Mileage is 108k and the head gasket was replaced before, at about 70k.

 

As I said before, it doesn't use a lot of oil and it has been running well overall. A bit of hesitation at low revs sometime and it does seem to have the odd "off day" but when on song it is certainly putting out more than 200bhp.

 

Fingers crossed it is the right side of £2000!

[Roger Blassberg 0]

Was any reason given for the previous head-gasket failure? Was the head checked for flatness, and was any work done on the valves/springs? There may be a residual problem there.

 

But, and I think it's a big but, you seem to have no evidence of a problem other than one opinion on compression pressure. All of us get "off days", which can be caused by a tank of poor quality petrol, disadvantageous atmospheric conditions such as warm low pressure air, even just a strong head wind!!

 

Mine has done 173,000 miles. After the head replacement and in standard trim, it gives 191bhp on Vince's rollers, uses about the same amount of oil as yours (including a very minor oil leak) and feels good and strong. Moral: there's plenty of life left in a VR at 108k.

 

Best wishes (to all including the new arrival)

 

RB

[Kevin Bacon 5]

, even just a strong head wind!!

 

You certainly notice that at motorways speeds!

 

The car is quick on the way to work in the morning when the air is denser and a following wind, but this week, the car has felt slightly slower on the way home - headwind and higher ambient temp!!

 

Science has an answer for everything :lol:

[emax 0]

Was any reason given for the previous head-gasket failure? Was the head checked for flatness, and was any work done on the valves/springs? There may be a residual problem there.

 

The original head was replaced by VW when the car was owned by the previous owner. They replaced it due to a mis-diagnosis and he got a full refund!

 

Basically, he kept seeing the occasional puff of steam appear from under the bonnet. VW diagnosed the head gasket and replaced it. On picking the car up, he drove about 20 miles and saw another puff of steam rise from under the bonnet! Turned out to be a split coolant hose!!!

 

The head is coming off tomorrow and they'll assess the problem from there. I'm hoping that it is "just" the gasket; if it is the rings, I don't know if it is worth spending close to £2k and I'd need to give this some serious thought.

 

While the head is off and provided the rings are ok, I'm going to get them to replace the tappets too so I reckon that all in (with the injectors being refurbed too) that I'll be looking at a bill of four figures.

 

If it were piston rings, what symptoms would I be seeing? I am seriously hoping it isn't!

[Roger Blassberg 0]

Kev,

 

looking back in this thread, you say that new rings entail a short engine rebuild. If it's just broken or worn rings, cannot they be renewed into re-honed bores? And cannot the block be overbored with new pistons if the bores themselves are worn?

I know that the 2.9 block is already 1mm overbored - is that the limit of reliability?

 

Comparing a 30mph head wind when driving home at 70mph, with the same wind as a tail wind when you came to work, the aerodynamic drag is over 6 times as much !! At 25 deg C. ambient temperature, your engine will produce about 5% less power (10 bhp) than at 10 deg C., all else being equal. It makes a big difference.

 

Best wishes

 

RB

[Scott 0]

Firstly before you do ANYTHING get a leak down test done.... and get the figures off them too....

[G60Dan 0]

something sounds fishy there. Get a 2nd opinion b4 you let them take it apart mate.A head gasket shouldn't go within that many miles!

[dr_mat 0]

Unless it was fitted by muppets......

[Gman 0]

Hope you get it sorted mate.

It is never good when things like this happen.

 

G

[Roger Blassberg 0]

If you had a new head only relatively recently, I would doubt that it's leaking valves or weak/broken springs. A head gasket is also most unlikely unless you have seriously overheated it or have failed to keep the corrosion inhibitor concentrations to specification.

 

I would most strongly agree with the others; don't let them take it apart without a second opinion, and get a leak-down test to confirm the low pressure. If it's going as well as you say, there's no rush, irrespective of the reputation of your spanner man.

 

If you have a four-figure sum to throw around, by the way, I'll PM my bank account details :lol:

 

Best wishes

 

RB

[Robbo149 0]

The car is quick on the way to work in the morning when the air is denser and a following wind, but this week, the car has felt slightly slower on the way home - headwind and higher ambient temp!!

 

That really is true, I thought it was me being daft, but I notice this every day to & from work. :)

 

Cheers,

Robbo

[Jim 2]

Not only quicker but feels much smoother too :)

[dan 0]

Yeah... I'd definitely get a second or even a third opinion. There's nothing as anoying as buying all the parts & paying someone to fit them just to find out later that the problem exists somewhere else. (Trust me, I know :mad: )

 

Did you get a new chip fitted with the Schrick?

[Kevin Bacon 5]

Kev,

 

looking back in this thread, you say that new rings entail a short engine rebuild. If it's just broken or worn rings, cannot they be renewed into re-honed bores? And cannot the block be overbored with new pistons if the bores themselves are worn?

I know that the 2.9 block is already 1mm overbored - is that the limit of reliability?

 

 

You can only rehone and re-ring if the bores are within ovalisation tolerance. This is why I suggested a 2nd opinion because I've not heard of bore number 2 going first on a VR.

 

If Emax said it was bore 1 or 6, then the usual routine answers would have followed, but bore number 2 is just plain weird at 108K!!

 

I think the bore limit for the VR block is 83mm. Used with J&E pistons, this gives a swept volume of 3.0. There are other crank throw and bore combos you can try which give more CC though.

 

The suggestion to rebuild the short motor was "Haywire" thinking I'm afraid, from a "Whilst it is out, you may aswell do X, Y and Z......" slant.

 

I'm not stinking rich or anything, but I just wouldn't lift an engine, scratch the bores up a bit and stick new rings in. For the sake of repeat labour and a marginally bigger bill, you may aswell get it all done properly to begin with.

 

Let's hope it doesn't come to that though :?

[emax 0]

I've just mailed them to ask for a leak down test prior to removing the head.

 

With a baby due imminently (tomorrow!), I don't really have time to find and take the car for a second opinion just now :-( Besides Star definitely have the knowledge/experience and I do trust them.

 

Just found the receipts for the old work:

 

The Head gasket was replaced by VW Listers in Coventry at 71,360 miles.

 

AmD replaced the Hydraulic Lifters at 74,500 miles. They found at this point that VW had fitted the cam bearing caps the wrong way round and the rear cam one gear tooth over-adjusted!!! No damage done though.

 

We're now sitting on 108,500ish.

[dinkus 10]

AmD replaced the Hydraulic Lifters at 74,500 miles. They found at this point that VW had fitted the cam bearing caps the wrong way round and the rear cam one gear tooth over-adjusted!!! No damage done though.

 

:shock: :shock: Which is why you never take your car to VW to get work done