Technical JTD loss of power/engine rev judder

[Iceman07]

Hi all,

My Stilo appears to have developed a new disease.

Setting off from some traffic lights the other night (the engine still cold, only started a couple of minutes before), setting off in first felt like third or fourth. Being a clumsy chap, I thought that I had actually tried to set off in third.

Anyway, the next morning, after driving off of my estate where I live, I'm setting off again, and it's the same. This time, I didn't get through the lights. So I knocked it in neutral, and it was struggling to rev towards 2000rpm. I engine itself sounded juddery and felt it too. Anyway, I kept revving it, and then, as it did the previous night, it all went fine. Thereafter, both journeys were fine.

It has been fine for a couple of days, but today on the way to work, again after only driving a few hundred yards, I started losing power in third. I changed down to second and I was steadily grinding to a halt. I pulled over, felt it juddering as I revved it again, but let it rev a bit for perhaps 20 seconds, and then it went fine again. On my way home tonight, not a problem.

Just had my timing belt done, and some other work, so I've spent quite a bit recently. Any ideas what this could be? Hoping it's nothing major.

Thanks in advance!!

 

[mhowse]

Hello

Do you have any warning indicators showing on dash, or error codes ??

Things that come to mind are erg valve stuck need of clean or blank off, maf playing up located down by airbox unplug electrical connector that connects on top of maf and see if car runs better if so then maf issue, crank position sensor does cause stalling with warm engine though usually fault codes show this,,also since you wrote you had cambelt work done recently roughly how long after this work did symptoms start may or may not be related to the cambelt timing. having current fault codes read would help

 

[Iceman07]

Thanks for your speedy reply!

I don't have any warning lights or anything come on.

I had the cambelt done about 2 and half months ago now. I've done plenty of miles since then, and it has been completely fine. This only started happening at the end of last week.

It seems that once it has this episode, it is fine. It doesn't last long either.

One thing I have noticed recently, when approaching traffic lights, I sometimes knocked the car into neutral before stopping. Occasionally, when I stop, even though it is in neutral, the revs drop a tiny bit, for a second, and then go back to normal. Don't know if this is related.

I'm not really that hands on mechanically unfortunately, and I'm the sort of guy that would probably make it worse by trying to do my own cleaning of valves etc! Just thought I would pick everyone's brains and see if I can pinpoint the problem so I can perhaps get into a garage with a bit of knowledge behind me

Thanks again

 

[mhowse]

Well with 2 months OK driving hope can rule out cam belt fitting problems

as you honest enough to admit your mechanical skills are not up to rocket science standard, you could give disconnecting maf connector ago if you felt up to it and see how the car runs better then point to the maf , as the fault is intermittent is does make finding the culprit a little more awkward, a link below on maf connector
https://www.fiatforum.com/stilo/130084-jtd-maf-issues.html

egr valve becoming clogged up with soot is common and cause loss of power, what mileage is on the car and how many miles have you been the owner, it may have never been cleaned and is common to blank it off, though think if that would require a helping hand due to mechanical skills.

 

[Iceman07]

I had the same problem again this morning, though worse. Foot to the floor in first, doing about 5 mph. Wouldn't rev to 2000rpm. Then all of a sudden burst into life. Looked around saw a lot of smoke coming out the back. Once it cleared, everything was fine again. Problem is, this only happens in inconvenient places!

I think I will call in a garage on my way home tonight and see what they say. I would suggest EGR and MAF to them. Just so they don't try doing me a headgasket or whatever (this has happened before!)

Are they pricey things to put right?

Surprised at the amount of smoke coming out, would this suggest EGR?

Oh and the car is now on 81,000. I've had it since 60,000. During all this time I think the thermostat has been stuck open too, so might have been overfueling. Never got round to getting it replaced.

 

[Peat]

With lack of power below 2/2.5k revs and then sudden recovery with lots of black smoke would indicate EGR problems. Get garage to blank it off and you will have no more problems in that area.

 

[Iceman07]

Ah right...

I will call in after work. Wouldn't an EGR problem be noticeable all the time though? As I say, after these episodes, the car is fine, and pulls like a train all way through the rev range. But during the episodes, it's a nightmare. Struggles to set off in first, engine sounds fluttery, and with my foot to the floor I will be doing about 4/5mph. Stationary, revs struggle to get to even 2000rpm. The engine feels 'wobbly' and fluttery, sounding a bit off. And then it's fine.

Would it be better to get the EGR blanked off or get it replaced? What are the pros and cons?

Thanks for all the inputs.

 

[mhowse]

With lack of power below 2/2.5k revs and then sudden recovery with lots of black smoke would indicate EGR problems. Get garage to blank it off and you will have no more problems in that area.

:yeahthat:

Lack of power and smoke are the symptoms of egr problem, even though it is not happening all the time it is operated by an electronic solenoid valve which becomes clogged up with soot at present yours may well be sticking and then freeing up to give the power back, you can purchase a blanking plate for few pounds from a popular auction site and ask a friendly garage to fit it for you if you do not feel confident to do the work yourself, it is a fix that many opt for to take away any future issues of the valve becoming choked up with soot and has no side effects on the engine or performance.from what you have described it would be best thing to get looked.at.

It would no doubt cost you less to get egr blanked than removing and cleaning the valve or replacing, you could opt to have the valve cleaned should the solenoid still be in good working order once cleaned, but bare in mind it would require cleaning again sometime in the future depending how long you intend to keep the car, once blanked you can forget about it should it become clogged up with soot or the electronic solenoid fail it would not matter as you would of had it blanked off..

 

[Stealth123]

I would agree with the EGR valve, had the problem this morning and will block it off this time.
However I did have other problems with pulling off after a red light etc, the engine just died or lost revs.
The problem was the hose connected to the injectors was leaking and left a puddle of diesel in the recess under the injectors always worth checking by taking the plastic engine cover off.