mk2 Posted August 31, 2021 Report Share Posted August 31, 2021 Just helped out someone over the WE with their rough running tdi, having come to me after spending over £500 with vdubs, who didn't diagnose it right! I said I'd be happy to stand up in court to tell them them what i thought of their 'professional' skill level. Huh! They changed the EGR valve. Wrong! I reckon @Rich, @Blue Loop, @Skajme or @RAB would be able to diagnose it in under 5 seconds. Took me about 30... Symptoms were obviously misfiring, running on only two cyls. until warmed up. Started ok, and had a loud tapping noise- really loud with the air inlet duct removed. VCDS showed a big injection quantity imbalance between cylinders at idle- trying to add fuel to cyl 1 and pull from 2 & 3. Obviously air starved on no.1 with the inlet valve not fully opening. It's amazing how vdub ECUs actually measure the rotation time between injection pulses and trim the injection timing to achieve a smooth idle. When a power stroke has more push than the other cyls, it obviously takes less time to rotate. So it adds fuel to the weaker cylinder and pulls from the others to try and even out the power strokes. Neat idea. This 2001 Lupo had 165k miles on it, with a decent history... Down to the breakers yard to grab a camshaft (and a tappet) from a 9N Polo, which was pretty much like new still. It always seems to be the lobe next to the pulley that goes, having seen a few worn cams at the breakers. The engine is at a slight angle, with the gearbox end being slightly lower. Straight forward job- just loosen the timing belt and tensioner. Pop off the valve cover and bearing caps. Pull the dodgy tappet. Pop off the pulley, swap over everything and back together again. You don't even need to remove the high pressure fuel pump or adjust the injection timing as everything is precision made. 4 Quote Link to comment Share on other sites More sharing options...
Rich Posted September 1, 2021 Report Share Posted September 1, 2021 I threw my old cam in the scrap car the other day and the traditional concave lifter/set. Still runs like **** on idle after changing it Quote Link to comment Share on other sites More sharing options...
mk2 Posted September 2, 2021 Author Report Share Posted September 2, 2021 I still wonder why the balance shaft and that wierd chain setup is there. The 3 cyl engines run just as rough without the balance shaft apparently (german lupo forum experiments). I discovered that you can tweak the idle slightly by messing with the injector lash adjusters. The rule is screw in to screw locking at max injection depth then back off 1/2 a turn. If vcds says an injector is chucking too much fuel in, i've found that backing off a bit more, like 3/4 turn does reduce the injection quantity very slightly. 👍🏻 On that concave and holed tappet, the oil must have been flooding out. I reckon not long until total catastrophic failure and game over there. Every car should have a magnetic sump plug like @CLAYTONJONES uses. Would certainly have been an early indicator that something was wrong. Quote Link to comment Share on other sites More sharing options...
Rich Posted September 2, 2021 Report Share Posted September 2, 2021 There was a lot of silver floating about my engine but I did catch it before the hole appeared. Tbh I could do with an injector loom. Mine used to run nicely too. Quote Link to comment Share on other sites More sharing options...
mk2 Posted September 2, 2021 Author Report Share Posted September 2, 2021 Yeah what got me is that the guys in vdub completely missed it. I mean come on, how can you miss a really loud tapping and think that it's a clogged/stuck/broken EGR valve. The guy who runs that car is not happy about it especially after I told him that there was probably nought wrong with the old EGR valve. Get rid and chip it... 👍🏻 More power. Blow the thing up properly. An AMF may as well have an exciting end of life rather than just wither and die with a duff cam or chain. The old injector loom is probably fine. Just crack all the brown plug covers off, squeeze the little spade terminal plugs a bit, so they're a tighter fit and whack 'em back in one by one. Will last forever. I did that to a Polo a while back and haven't heard a squeak since. Stupid bad design that loom wiring. 3mm spades are designed to take up to about 3-4A. The injector coils can sink over 20A... Mmmm. Quote Link to comment Share on other sites More sharing options...
Rich Posted September 3, 2021 Report Share Posted September 3, 2021 Been there, done that, still wants a loom. Amf is a surprisingly nippy thing Quote Link to comment Share on other sites More sharing options...
tigcraft Posted September 5, 2021 Report Share Posted September 5, 2021 That was an interesting read! Good to know the forum knows more than others but bad to know the expert who charges eye watering amounts don’t! Quote Link to comment Share on other sites More sharing options...
RAB Posted September 12, 2021 Report Share Posted September 12, 2021 That's why it's important to run with the correct grade of oil with a Tdi. The injectors put an enormous amount of pressure on the camshaft. If you don't change the oil at the required intervals (and/or use an incorrect oil), you'll get lots of wear on camshaft shell, particularly the upper ones. That's what has happened here. Even if you do the correct thing, you still get wear! RAB Quote Link to comment Share on other sites More sharing options...
tchouki85 Posted July 27, 2022 Report Share Posted July 27, 2022 Oula I discover the joys of a bad oil used, on golf4 we have the same premature wear of the hydraulic tappets and the camshaft around 280000km and precisely since I will do the distribution on the Lupo 1.4tdi which is coming at 248000km I will change them in prevention, I hope they will not be like yours Quote Link to comment Share on other sites More sharing options...
mk2 Posted July 27, 2022 Author Report Share Posted July 27, 2022 @tchouki85, you MUST change the chain and tensioner now! 248000km with original chain and tensioner is insane. Unless it was already done. They only last around 200000km before they wear out. Lots of pics of your tensioner when you have removed it please... Quote Link to comment Share on other sites More sharing options...
tchouki85 Posted July 28, 2022 Report Share Posted July 28, 2022 On 7/27/2022 at 10:14 AM, mk2 said: @tchouki85, you MUST change the chain and tensioner now! 248000km with original chain and tensioner is insane. Unless it was already done. They only last around 200000km before they wear out. Lots of pics of your tensioner when you have removed it please... yes yes the distribution has already been changed at least twice already Quote Link to comment Share on other sites More sharing options...
mk2 Posted July 28, 2022 Author Report Share Posted July 28, 2022 On the 1.4 TDI engine there is a camshaft timing belt AND a balance/oil pump chain. (And an alternator belt) Quote Link to comment Share on other sites More sharing options...
tchouki85 Posted July 29, 2022 Report Share Posted July 29, 2022 yes i know thank you😜 Quote Link to comment Share on other sites More sharing options...
Rich Posted July 29, 2022 Report Share Posted July 29, 2022 I recently made an oil pump chain into a keyring. Quote Link to comment Share on other sites More sharing options...
tchouki85 Posted July 29, 2022 Report Share Posted July 29, 2022 oh well and what does your keychain look like Quote Link to comment Share on other sites More sharing options...
tchouki85 Posted July 31, 2022 Report Share Posted July 31, 2022 awesome I received my hydraulic tappets, all I need is the Spy camshaft seal and the flange screws to attack the site Quote Link to comment Share on other sites More sharing options...
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