gti6 high rpm flat spot

[aaddzz123]

Hi guys! I've not long had my gti6 and couldn't help notice it feels sluggish at higher RPM. I'm not sure when but around 6-6.5k it feels like the power dies down... Is this normal for the 2.0 or a common problem that can be solved? I've also noticed the tachometer is ridiculously slow. Anything that can be done to improve the responsiveness of that?

Cheers in advance .

Adam.

[7057sam]

Get the cam timing checked

[aaddzz123]

Right I welded my exhausy last night to cancel out it being anything to do with that. I also checked the breather and cleaned it out as there was oil coming from the filler cap to suggest it's breathing heavy. Tried leaving it open and took for a drive but still the same. I haven't checked the timing yet as I ran out of time. But I'm fairly sure it isn't the timing as it runs alright for the rest of the Rev range. It is a little lumpy though on idle... It's a bit tappy too from a recent head rebuild. I'm wondering if all the clearances are out, some too tight and some too loose. Causing the tap and flat spot maybe?

Has anyone done the clearances on this engine? I presume its a bucket and over bucket shim design? Anyone know what the tolerances are supposed to be?

[powerandtorque]

Hydraulic lifters on a '6 so the top end should be quiet - the clearances can't be out, unlike a conventional shimmed setup.

Could be a tired / dead lifter, or it could be that you've some dinked valves from someone making a mess of the cambelt install or from a badly repaired post belt snap engine. It's unfortunately a well known problem with GTi-6 engines thanks to the lack of piston-valve clearance, the timing hole slipping on the crank pulley and the engine having a habit of prematurely snapping belts.... do a search for "tapper" and you'll find plenty.

Cam timing can easily be a little out and it run OK for much of the rev range - they're very sensitive to cam timing.

[aaddzz123]

I see! I've never dealt with hydraulic lifters before. How would I be able to test them to see if they're worn out?... The engine has recently been built apparently due to the belt snapping for a second time. He claims to have changed all the valves and used a 1mm thicker gasket incase of any clearance problems with the valves but I have no proof of it... A friend of mine said that most of these engines tap after being rebuilt. Is that due to a common mistake during the build or just cutting corners and reusing damaged valvetrain? I'll do a search for tapper now. And check the timing tomorrow.

Cheers !

[powerandtorque]

A lot of them do indeed "tap" after being rebuilt following a cambelt failure - it's down to the rebuild not being done properly and damaged valves or guides being re-used (or because it was subsequently damaged being refitted and timed up again)

Everything being good these engines should be quiet and not tap, rattle or anything else.

The problem is the timing is that you can't rely on the timing hole on the bottom pulley being correct, as it's on the outer section that's bonded to the inner with rubber... which breaks up and allows the pulley to slip, leading to the timing hole being in the wrong place. Sometimes there's a mark on the inner pulley which lines up with the hole on the outer to confirm that it's good, but not always. Many a person has ruined an engine blindly trusting that hole is in the correct place...

[aaddzz123]

Greeeeeat lol. So are there any other ways to know if the crank is in time? Is the hole supposed to line up when it's at TDC?

[welshpug]

nope, the hole should line up mid stroke.

[aaddzz123]

Typical lol. I don't suppose there is a locking off hole in the gearbox and flywheel like on the XUD?

[powerandtorque]

I just use the pulley from a 205 GTi XU 8v solid pulley to verify the hole position / timing, but that's not much help if you don't have one to hand.

[welshpug]

Typical lol. I don't suppose there is a locking off hole in the gearbox and flywheel like on the XUD?

nope.

[adam b]

It's a complete arse if it has slipped.
Tbh they rarely tend to pull much more after 6500, especially if the cams have been slightly advanced.

[Pebbles167]

Two of my Gti6/Rallye's were standard and both tailed off a little after 6500rpm and so changed gear then. The only one that pulled up to redline was a Rallye that had slightly different cams, (pt-80 I think) and I suspect mainly because it was slightly down on power anyway. Unless it is severe, I wouldn't worry about it.

[aaddzz123]

Cheers guys.

I've not yet checked the timing but I'm 90% sure it's spot on. It runs absolutely fine up to 6.5k. If it's common for them to drop off then I'm no longer concerned !

[Niall]

Yeah the power hits its peak at 4.5k and really does tail after 6.5-7 so i wouldn't worry tbh. Theres no need to rag these 6's to the red line!

[cully]

Theres no need to rag these 6's to the red line!

Hah! mine pulls all the way to the limiter! these engines are designed to be reved as they are square stroked

[adam b]

I do but just for the induction noise. It drowns out the bad noises...

[welshpug]

TICK TICK TICK TICK......









































BOOOOM!

[7057sam]

I do but just for the induction noise. It drowns out the bad noises...

K&N induction+decatted magnex stystem could drown out a atomic bomb  

[Ruan]

Never understood this with regards to "change at 6500", I assume the cams in mine were always quite retarded! Mine used to live for the 7250rpm action, had a reasonable midrange, but was making power just before the limiter, if anything, I always felt like it could benefit from another 250-500rpm, it certainly didn't feel like it was getting wheezy up there... Torque was tailing, but not enough to make it drop power!

I've driven a few that have probably a strong midrange but have felt pretty flat up high, but always thought they were a bit boring tbh...

[Midnightclub]

Never understood this with regards to "change at 6500", I assume the cams in mine were always quite retarded! Mine used to live for the 7250rpm action, had a reasonable midrange, but was making power just before the limiter, if anything, I always felt like it could benefit from another 250-500rpm, it certainly didn't feel like it was getting wheezy up there... Torque was tailing, but not enough to make it drop power!

I've driven a few that have probably a strong midrange but have felt pretty flat up high, but always thought they were a bit boring tbh...

Agree with you here! Mine felt like it pulled hard all the way to the limiter, used to love it. Anything past 3.5-4krpm and it'd go well.

[Moonwalker]

Two of my Gti6/Rallye's were standard and both tailed off a little after 6500rpm and so changed gear then. The only one that pulled up to redline was a Rallye that had slightly different cams, (pt-80 I think) and I suspect mainly because it was slightly down on power anyway. Unless it is severe, I wouldn't worry about it.

My Phase 2 Gti 6 pulls in every gear up to Red Line! Must have some up rated stuff I don't know about then!

[Toms306]

Every gear? Would like to see you redline it in 6th...

Mine pulled right round to near the redline tbh, had to push it past 4.5k to find any real power!

[welshpug]

maybe boring, but certainly would be quicker.

[aaddzz123]

I find the mid range is awesome. Pulls really well to 6-6.5. Flat after that. I did notice though that my mid section exhaust is squashed a little in one place. Certainly could be creating a little too much pressure. I'll soon see when I make my new exhaust in a few weeks .

[adam b]

Mine red lines in top gear...?!

Anyway I think my car is fairly quiet with a Peugeot Sport magnex, decat and induction kit. Only 87db at 4.5k static.
This engine likes to rev out but my old rallye with advanced cams was all done by 6800.

And yeah she does make a lot of noises hehe

[Ruan]

maybe boring, but certainly would be quicker.

Oh I don't doubt it!

But if I wanted a motor that didn't require to be spanked the shit out of, I'll go drive my "shitty diesel" as most people call them

[lolsteve]

Pulls all the way to 7.5k

[Moonwalker]

Every gear?  Would like to see you redline it in 6th...

Mine pulled right round to near the redline tbh, had to push it past 4.5k to find any real power!

To be honest I've never got it anywhere near the Red Line in 6th! And I don't know if it could be done? Lol!

I'm still getting used to driving her, don't want to push it too far. I'm gonna take her to Crail once I've got the exhaust done, then I can open her right up. Hopefully getting the wheels refurbished soon too.

[Midnightclub]

A stock GTi6 will not hit the limiter in 6th, 100%. You'd need a massive down hill section at least!