I think to be honest it runs too well for the belt to be one tooth out. It starts very well, and idles very well too, and although I find it sluggish, it's not so bad as I would expect with the cam timing out. But there again, who knows unless it's stripped and the  timing is checked

On 12/04/2022 at 14:39, Bison said:

not being able to put the car into 5th until over 50mph is a pain

I can trickle along in 40 mph limits in 5th but if a hill or need to accelerate I drop down to 4th.
My fuel use is about 57mpg long term but I have no problem getting over 60mpg on a run, even into Lincoln only about 4 miles I can show 60mpg on the Maxidot.
When up to temperature on the level it does a little over 100mpg at 30mph in 4th, again if a hill or accelerating there is a need to change down.
It's the most free running car I have had.

I think I'm expecting too much at low revs, as has been said, it needs to be driven like a petrol engined car. Although that shuddering is pretty bad, 5th at 50 and if you accelerate you can still feel the shuddering.

I'm going to look into a remap, and also having the fix undone.

 

@Bison I think you are suffering with sooted turbo vanes. There are options out there such as the fabled Mr Muscle treatment, or an intensive Archoil treatment in the tank over a few weeks/months. 

 

When squirting DPF cleaner into the oxygen sensor some of the foam expanded unintentionally back towards the turbo, following this the car was much more tractable and now runs down to 30mph in 5th without the shuddering you describe. (Not that I drive like this, it was a test!)

 

I used K2 DPF cleaner at £14 delivered if you're interested. 

Now that's worth a try, the Wynns turbo cleaner stuff seems to get good reviews.

Thanks.

Hi Folks,

Just did the turbo cleaning with the Wynns stuff. I looked at the vanes before cleaning and to be honest they didn't look that dirty, but there's a definite improvement in the running, it idles much better quieter too, and the pickup from tickover is better, the shuddering is still there, but much less pronounced. Next will be the DPF clean, and I may put some EGR cleaner in after that.

I'll keep you informed.

Thanks,

Alan.

On 19/04/2022 at 16:52, Bison said:

Hi Folks,

Just did the turbo cleaning with the Wynns stuff. I looked at the vanes before cleaning and to be honest they didn't look that dirty, but there's a definite improvement in the running, it idles much better quieter too, and the pickup from tickover is better, the shuddering is still there, but much less pronounced. Next will be the DPF clean, and I may put some EGR cleaner in after that.

I'll keep you informed.

Thanks,

Alan.

 

 

Keep going Alan.........i feel your pain..!

Hi,

More info.

I cleaned the DPF and it made a little difference, but hardly noticeable. What I did notice when cleaning the turbo was an awful lot of crank case pressure when the hose wasn't fitted, that is, I ran the engine with the turbo hoses disconnected, as per the instructions, and the crankcase breather  hole on top of the cam cover was puffing away good style. Now I should also say the car doesn't use oil, there are no oil leaks, and it doesn't smoke. Are they all like that?.

Alan.

I meant to ask. If the MAF sensor was faulty, but no code coming up, would unplugging it allow the car to run better?, thereby diagnosing a faulty MAF?.

50 minutes ago, Bison said:

I meant to ask. If the MAF sensor was faulty, but no code coming up, would unplugging it allow the car to run better?, thereby diagnosing a faulty MAF?.

 

Try it.  I found that worked on my 1.9 TDI Mk4 Golf c. 20 years ago. 

Disconnecting the MAF made no difference, oh well, looks like map check is next.

I too have the dreaded CAYC engine, I think you need to use more revs - a lot more.

 

Unless I rev mine to 2500rpm for a few seconds on the drive before I pull away it simply has no 'go' and pulling out of the uphill junction at the end of my road is 'interesting'. 

 

Even then, 3rd and above are horrible under 1500rpm, and I get pronounced diesel knock around tickover - if I pull away slipping the clutch with no throttle it's fine (in slow traffic), but any throttle no matter how gentle produces diesel knock.

 

If I was capable I would have replaced the 1.6tdi lump with a 2.0tdi - in the long run this would have been MUCH cheaper. 

 

 

12 minutes ago, b1ackb1rd said:

if I pull away slipping the clutch with no throttle it's fine (in slow traffic), but any throttle no matter how gentle produces diesel knock.

There must be something wrong, mine has never done that.
I have to agree about it's unhappy at below 1500 revs in the higher gears but I take it because it's the only Yeti diesel without a DMF.

23 minutes ago, Urrell said:

There must be something wrong, mine has never done that.
I have to agree about it's unhappy at below 1500 revs in the higher gears but I take it because it's the only Yeti diesel without a DMF.

 

I agree, I just need to know what the issue is - I suspect it's a clogged intake manifold as I've changed everything else. 

At some point I intend to remove the MAP sensor, blast the intake with brake cleaner via the EGR mixer with a long flexible spray pipe and let the muck evaporate/drain out of the sensor hole. 

That sounds exactly the same as mine Blackbird, to a "T". I've cleaned the anti shudder valve, turbo, MAF etc, to be honest, they weren't really very dirty at all, certainly nowhere near as manky as some of the photo's I've seen posted, and it has made really no difference. It seems my car has not had the fix, at least there is no baffle mesh of any sort in the intake system, so I can't blame that. I think my only resort is an emulator or a remap.

The thing is, I spoke to my pal who I bought the car from, he bought it new, and said it was like that from day one?.

Alan.

58 minutes ago, b1ackb1rd said:

I suspect it's a clogged intake manifold as I've changed everything else. 

At some point I intend to remove the MAP sensor, blast the intake with brake cleaner via the EGR mixer with a long flexible spray pipe and let the muck evaporate/drain out of the sensor

If you did that would it not just move the problem to the DPF?
Have you removed the throttle body to clean the tar out of there?

Well, if it does turn out to be a clogged inlet manifold, please do let me know.

Alan.

36 minutes ago, Urrell said:

If you did that would it not just move the problem to the DPF?
Have you removed the throttle body to clean the tar out of there?

 

Throttle body (ASV) has been cleaned out twice in 12 months, it was bad on both occasions probably because one of my injectors was over-fuelling. 

 

I found that the DPF back pressure has been greatly improved by removing the sensor and applying cleaning foam spray and at around £20 a throw I will do that as part of regular maintenance. The DPF differential sensor gets a a reset via VCDS each time. 

 

I'm convinced the diesel knock originates either due to a duff sensor changing the mix and making the car run very lean around tickover, or on the inlet side due to clogging. 

Edited 15 May, 20224 yr by b1ackb1rd
edit

I cleaned the DPF in the same way a couple of weeks ago, it made perhaps a very slight difference to the idle, it was very slightly smoother, apart from that, no difference. Mine idles pretty smoothly, when warm, when starting from cold it rocks slightly for perhaps a minute or so then smooths out. It rocks less when cold now the DPF cleaner has been used, but only slightly.

1 hour ago, b1ackb1rd said:

Throttle body (ASV) has been cleaned out twice in 12 months, it was bad on both occasions probably because one of my injectors was over-fuelling. 

Have you changed the direction of the EGR outlet into the inlet 180 degrees to stop it spraying onto the throttle body?

Mine faces towards the ground, is it worthwhile changing it to face towards the engine?. As I said, the throttle body/anti shudder valve was a little dirty, but not really too bad, and cleaning it made no difference.

If I have time next week I'm going to check the timing on the cam belt, it was replaced maybe 9K ago, before I got the car, clutching at straws perhaps, but worth checking.

2 hours ago, Urrell said:

Have you changed the direction of the EGR outlet into the inlet 180 degrees to stop it spraying onto the throttle body?

 

Yes, did that as soon as I bought it

I have the EGR deleted in a map, and blanks fitted behind the EGR mix tube to seal it off properly. 

 

(I've just watched programme about Op Tiger that made me realise the fuel temp sensor (reading in Fahrenheit) is way off, I'll change that again)

So after a few weeks of calm, my CAYC Yeti is playing up again;

 

Checked the car using live data with Carista today, it showed coolant temp at 78 degrees C, but 90 degrees C showing on the clocks - which sensor do I need to change?

 

Also I noted a big difference  between air mass value (actual) 36g/s and air mass value (specified) 156mg/stroke, can anyone comment on the significance of this?

Hi

 

Thanks to software intervention the temp gauge needle in the dash will show a solid 90 for any coolant temp in an "acceptable" range of let's say 80 to 100 degrees C.  Presumably done to stop people trotting back to the dealers.  Yours sounds a tad on the low side.  I don't know if there are separate sensors for the ECU and the gauge.

 

The global and cylinder air mass values might be measured in different units, i.e. grams per second or grams per stroke (i.e. revs dependent), so you can't directly compare the two exept by calculation knowing the RPM.