Just bought an SX4 1.9 diesel, 08 plate with 92k miles.
It drives really well apart from the slight hesitation around 1800 to 2000 revs.
Research on here points to EGR and it has been widely discussed.

Question: If I blank the EGR with a plate am I better with solid plate or one with a hole?
Also, if fitting a plate, should I still clean out the EGR valve at the same time?

Thanks

welldc said:

Just bought an SX4 1.9 diesel, 08 plate with 92k miles.
It drives really well apart from the slight hesitation around 1800 to 2000 revs.
Research on here points to EGR and it has been widely discussed.

Question: If I blank the EGR with a plate am I better with solid plate or one with a hole?
Also, if fitting a plate, should I still clean out the EGR valve at the same time?

Thanks

Click to expand...

The restrictor / swirl plate with holes, which is a standard Fiat part improves things considerably. You still need to clean the EGR when fitting it. I did a guide for the 1.9 16V engine. A blanking plate (no holes) is nsnot approved and makes the car illegal ro drive on the road. On later cars it will cause a engine malfunction light to come on. I don't know if this applies to your SX4. If it does you need an ECU remap (or posibly a bodge connecting the EGR circuit to the MAF circuit). If you fit lanking plate or get an ECU remap you have to tell your insurers or you insurance may be invalidated. This does not apply to the restrictor / swirl plate as it is a Fiat part. By telling your insurer you are providing proof that you are breaking the law. Many insurers will not cover re-maps. For example Directline specfically will not cover re-maps or modifications.
My recommendation is to clean the EGR and fit a restrictor plate.

Robert G8RPI.

Thanks Robert.
Sounds like a Saturday job when the weather improves.

The 4 hole restrictor plate is completely worthless and non functional.
It just acts as a placebo sollution, and it only deletes the malfuntioning of any EGR..
(Btw ,it's only used by Greenpeace members.....:devil
Blank the EGR with a solid plate ( Ebay) and have a chiptuner delete the EGR from the ECU.
Don't worry about illegal behavior, nobody, again NOBODY will ever know or care, trust me.
It's more illegal and bad for health to drive around in a black smoke spitting, hesitating Diesel car.

Peter Pick-Up said:

The 4 hole restrictor plate is completely worthless and non functional.
It just acts as a placebo sollution, and it only deletes the malfuntioning of any EGR..

Click to expand...

Can't quite agree Peter. Yes the restrictor plate is not the perfect *performance* solution *but* it does radically improve all the EGR issues.

There is another issue here:

1) Some older engines you can blank the EGR off without the engine management system throwing a wobbly

2) Other ECUs will require EGR delete, i.e. remapping which is potentially an insurance issue.

With 2) whilst a simple EGR delete seems harmless non performance mod in as much as no extra horse power is released etc. etc. IT IS STILL A MOD and one's insurance could be null a void if this is not disclosed and accepted/agreed by the insurance company.

Here in the UK insurance companies duck, dive, and wriggle to get out of any claim even more so on a big claim. Personally I don't want to be paying monies that would have otherwise been covered by an insurance policy for the *rest of my life* (worst case) due to a benign engine mod that was not agreed by the insurance company.

The official Fiat restrictor plate would never ever count as a vehicle modification. Similarly if Fiat were to officially 100% blank EGR and update the ECU then this would not be an *unofficial* modification.

Read: "non functional and worthless, it only slows down EGR trouble".
That's all that can be said about the 4 hole placebo plate, it doesn't improve anything, and it is by far not the sollution for a bad designed EGR system, it doesn't even comes close...

As for this insurance issues; give clear, real life examples and facts or stop mention it.
Same for this 4 hole restrictor plate: give figures and proof, before and after, and I mean REAL figures or be quiet ( and join Greenpeace...).

:devil:

Insurance:
https://www.directline.com/lib/pdf/dl-car-policy-document.pdf
Pages 7 and 28.

Restrictor:
On my 19.16V mJTD EGR valve opening increased 15-20% with restrictor plate installed.

I'm a professional engineer and have worked in electronics, aviation fluid systems and biotechnology. I'm not speculating on what the restrictor plate does, its basic fluid dynamics. EGR is not perfect but avoidable pollution is not acceptable.
Peter keep making references to Greenpeace members, he can't be talking about me, I own several Curies of radioactive material and was part of the team that designed, built and ran the fastest car in the world. That used 50 gallons to the mile, not very green

Robert G8RPI.

Only quoting books...??
Please read my questions above, or shut up.

It's not important how much % your particular valve is opening, please give us pollution figures....before and after....

So you designed the fastest car in the world, and you drive an old Croma diesel....:nutter:

The pollution figures before and after fitting the restrictor plate will be the same on an engine with closed loop EGR control (mJTD). The point of the plate is to improve mixing of the exhaust gas and inlet charge and to force the EGR valve to open further. Both these help with the known problems of EGR sticking and intake deposits. I can't give before and after figures for fitting a blanking plate because I won't fit one. Also measuring NOx is difficult requiring very expensive equipment.
On the books, it's a legal document that confirms my statement that the fitting of a blanking plate or re-map can invalidate insurance.

I am now going to ignore your trolling.

Robert G8RPI.

g8rpi said:

The point of the plate is to improve mixing of the exhaust gas and inlet charge and to force the EGR valve to open further. Both these help with the known problems of EGR sticking and intake deposits.

Robert G8RPI.

Click to expand...

You seem to know more about this than Fiat engineers, please explain further, kind of interesting I would say, after all you're a professional in engineering fast cars...

g8rpi said:

I am now going to ignore your trolling.

Robert G8RPI.

Click to expand...

FINALY... but not very professional...

:woot:

Back to the original poster:
Ignore the little conversation above, just fit a blanking plate (Ebay) and you'll be fine, don't get fooled by restrictor plates or whatever...

@welldc

One other side-effect of totally blanking the EGR system is increased warm up times. This can be an issue in cold weather. There is an exhaust gas to coolant heat exchanger. The primary purpose is to cool the exhaust gasses, but this does of course heat up the coolant. Blanking the EGR stops this exchange and more heat "escapes" down the exhaust system increasing warm-up times.

Robert G8RPI.

He is right, it takes a little longer to warm up my blanked Alfa GT jtd, but that's no real problem, as most of the diesel equiped cars run long distances, so a few more minutes to warm up the engine won't harm at all.
It's just like the old days, when there were no EGR valves, and diesel cars still got warm....!

Well, I've compromised a bit.

I've got a blanking plate with a single hole. Planning to clean up the EGR and fit the plate.

At some point I will have a look at getting it mapped. Just a bit wary at 92k miles until I get to know the car a bit more.

I had an Octavia2.0TDi which was mapped and it was fantastic. Overtaking was a doddle and in 56000 miles it averaged 60mpg without any issues.

Thanks for your input guys.

welldc said:

Well, I've compromised a bit.

I've got a blanking plate with a single hole. Planning to clean up the EGR and fit the plate.

At some point I will have a look at getting it mapped. Just a bit wary at 92k miles until I get to know the car a bit more.

<SNIP>

Thanks for your input guys.

Click to expand...

Hi,
Why did you go for a single hole plate as a compromise? The Fiat plates have either 3 holes (oval plate normally used on 8V engines) or 4 holes (square plate used on 16V engines). The reason for multiple smaller holes is to increase the velocity of gas through the plate and thus the tubulence behind it and improve mixing. On the 16V it also helps balance the flow between the two poppets used in the EGR valve (I know about this having worked on a system that divided a single flow into 16 with accuracy of 5%). A single hole will help but is not as effective as the 3/4 hole designs. Don't be tempted to drill exra holes in the plate you have as that will reduce th overall restriction.

Robert G8RPI.

The amount of holes makes absolutely no difference, the believe about "mixing" is nothing but wishfull thinking.....:devil:
The 1 or two or more holes are only there to prevent the check engine light to come on, by still allowing a rather large amount of used exhaust gas to enter the combustion chambers again...( and gumming up everything...)

Peter Pick-Up said:

As for this insurance issues; give clear, real life examples and facts

Click to expand...

Real life example = ME.

I specifically asked my insurance company about:

1) blanking EGR

2) removing DPF

Both were not allowed, indeed I could not even pay an increased premium to get either of them covered.

The use of an official Fiat EGR restriction plate was however perfectly acceptable and covered.

I also have good experience of negotiating vehicle modifications when I was doing motor sport in my then Uno SX.

Insurance companies can differ on what they will or will not allow. The only way to ensure you are actually covered for any modifications is to ask. Failure to do so could result in severe consequences.

In my own experience I found that the restrictor plate improved matters for me with respect to EGR valve clogging. There was no noticeable performance effects and with respect to the emissions I can't say as NOX is not measured, however the CO and particulate measurements showed no real change when looking back at annual MOT test results.

Peter Pick-Up said:

The amount of holes makes absolutely no difference, the believe about "mixing" is nothing but wishfull thinking.....:devil:
The 1 or two or more holes are only there to prevent the check engine light to come on, by still allowing a rather large amount of used exhaust gas to enter the combustion chambers again...( and gumming up everything...)

Click to expand...

To put your own requirements on this please provide evidence that there is no difference between 1 and 4 holes in a restrictor plate. Why do you think Fiat designed it with 4 holes rather than 1? Even with laser cutting or stamping 4 holes cost more to make. Are you an expert on flow dynamics or had any training or experience in the field? Remember with closed loop EGR control (the type that generally causes the MIL to come on) the total amount of exhusr gas added does not change when a restrictor plate is fitted. The only thing that changes is the EGR valve opens further and the gas path / velocity changes.
Your prejudice against EGR does not change the laws of physics or fluid dynamics. Orifice plates and jet mixing are common applications. Try http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19950017970.pdf for some light reading.

Robert G8RPI.