2.0HDI juddering solved

[Kyleonsite]

My few month old to me 2.0HDI has had an increasing judder at 30mph in 4th gear - ie low engine speeds/medium loads. Googling showed this was an issue with 2.0HDI's. I've substantially improved it by-

1. Disconnecting and plugging the EGR valve vacuum line. It doesn't throw up the EML

2. Replacing the MAF - my fuel economy was poor and I could see it was over fuelling (smokey at night with following headlights). A failed MAF doesn't throw up the EML

3. Replaced the upper engine mount buffer - my original buffer had a clearly visible few millimeter gap between the elastomer and body allowing the engine to move considerably fore and aft. Lemforder make an alternative 'Group N' design buffer that fitted far tighter than the original.

4. Italian tune up - due to the torquey nature of these engines it's possible to drive them without getting any serious heat into these engines. Mine was definitely clogged up but a full load/full rev range thrash through Wales cleared it.

It's far better now - it will pull 30mph in 4th gear from 1k revs. It's not 100% but I think that's down to the general poor quality of the Siemens ECU fuelling. The engine buffer made the biggest difference none of the other engine mounts were changed.


New engine buffer on top - original underneath.

[Kyleonsite]

Follow up note to my earlier post.

My Partner is used mainly on short commutes so it wasn't long before the engine was a bit coked up and the juddering returned. Over the last six months I've replaced all the engine mounts apart from the small 'dog bone' rear lower bush as it looked okay. Non of the replacement main engine mounts made a difference including fitting a polyurethane lower front bush.

Today I've finally changed the small dogbone bush and also I've 'shimmed' the upper right hand mount as per the photo (2x 3mm plastic building shims)

Both these have made a considerable difference - the juddering is still there albeit reduced but I think that's due to the large 2litre displacement of the engine and the lack of dual mass flywheel and I don't think I'll eradicate it entirely.

[saskak]

Thanks for this. I have a similar judder in my 1.6HDi. I thought of similar types of shims, but if they are displaced they can go towards the auxiliary belt and lodge in there somewhere. Maybe I will have to try to secure them with a wire.

[ffrenchie]

It's down to the gearbox and diff ratio, I don't try to run at 30mph in 4th gear I change down to 3rd. It's alright coasting downhill at 30mph in 4th gear but I know it will rock the engine trying to do it on the flat or uphill.

[Kyleonsite]

I agree - it's slightly long geared for 4th@30mph but I think its also a combination of lack of dual mass flywheel, the Siemens based ECU/ torque levels being a bit low and soft engine mounts.
I've changed all the engine mounts on mine with decent OEM items (Corteco etc) and a harder PU lower dogbone bush but they are still 'soft' and you can easily rock the engine by hand. I noticed that over winter - colder morning's were better from a juddering point as the engine mounts were harder/stiffer.

GroupN rally spec harder engine mounts are available for the 206 and would fit but they are considerably more expensive than OEM

It's also noticeable that if you deliberately invoke juddering by the operating at low engine loads in 4th gear@30mph but then 'floor it' the juddering stops as the engine goes under full load/torque levels increase. I did read somewhere that a HDI tuning state1 130hp ECU flash stopped the juddering as the engine is producing more torque for identical engine revs.

I don't intend to drive everywhere in 4th@30 as low engine speeds/high loads aren't good for crankshaft/big end lack of oil pressure and wear or for feeding low frequency/ high value harmonics into the gearbox shafts and Cv joints (hence why dual mass flywheels exist) but I do find it annoying that PSA Group got the design/calibration a little wrong in this juddering aspect.

This morning's commute over a repeated familiar route showed vast improvement over previously. I think I'm going to tinker further as I have a different idea for the (currently shimmed) upper engine mount and I'm a process engineer and don't like things beating me!

[Blackshuck]

I've noticed that the juddering seems to be linked to the front tyre size / wear .
When running brand new tyres , my van seems to pull 4th @ 30 mph OK , but as the tyres wear ( & the gearing changes ) then the judder returns .
At first I thought there was a problem with the engine , until I had new tyres fitted & it went away again .....

[Kyleonsite]

Update - checked today and both plastic 3mm shims had fallen out. I thought as much as the juddering had returned. They were both sat harmlessly on the bodywork below.
I've replaced them with a pair of 5mm shims to see what happens.

[saskak]

Update - checked today and both plastic 3mm shims had fallen out. I thought as much as the juddering had returned. They were both sat harmlessly on the bodywork below.
I've replaced them with a pair of 5mm shims to see what happens.

Yeah, that is what I thought, they would just fall off. maybe a wire to go through them and around the mount.

[Kyleonsite]

Ummmm..... another update! Even the 2x5mm shims have fallen out - shows how much engine movement there is in everything.
However one side effect of the shimmed restriction is how 'harsh' it made the engine & clutch. It was very noticeable with the 5mm shims when setting off that the car/drivetrain had lost some 'softness' and the clutch take up was more abrupt.

I've taken the shims out and need to have a rethink - my initial thought process of trying to physically restrict the engine movement is flawed. The juddering would probably be dealt with had PSA fitted hydraulic engine mounts (as my Volvo has) but the Berlingo is a budget car built down to a price.

https://transgold.com.au/hydraulic-engine-mount-work/

[saskak]

Ummmm..... another update! Even the 2x5mm shims have fallen out - shows how much engine movement there is in everything.
However one side effect of the shimmed restriction is how 'harsh' it made the engine & clutch. It was very noticeable with the 5mm shims when setting off that the car/drivetrain had lost some 'softness' and the clutch take up was more abrupt.

I've taken the shims out and need to have a rethink - my initial thought process of trying to physically restrict the engine movement isn't correct.

Perhaps thick rubber shims around the mount, that should certainly help and might not be that harsh as plastic shims.