C5 hesitation

[MadMalx]

My 1.8 C5 has a misfire/hesitation between 1700-2200rpm under partial/steady throttle. Does anyone have any idea what could cause this? It seems to happen mainly once warmed up, but isn't there if you 'floor' it..

[Clogzz]

That’s the EGR valve opening and closing.
My 2.0i does it around 2000 rpm.

[MadMalx]

It seems to be getting worse, or I'm noticing it more, making the car 'jerk' around 2k, so if it's egr related I think it might be near the end of it's life.

[Stickyfinger]

With mine, I had a similar fault, it turned out to be the electrical connections, opened the plug (PITA to get to), sprayed contact cleaner (EVERYONE should keep this stuff these days as standard equipment) and reconnected it, no problem since....best of luck

[Clogzz]

The EGR valve can be cleaned or disconnected.
Simplest is to pull the plug off to feel what difference it makes.
Unplugging will cause display of the anti-pollution fault, and after reconnecting it takes 3 weeks for the fault display to disappear.

[MadMalx]

I'll try the contact cleaner, but have tried to clean egr internals before and not had much success - always ended up buying a new unit...

[Stickyfinger]

I'll try the contact cleaner, but have tried to clean egr internals before and not had much success - always ended up buying a new unit...

Not the EGR itself....the electrical connector was where my fault was...

[Monkeyfeet]

I haven't had a petrol with an egr - but If it's the egr and it's coked-up partially open then unplugging it might not make much difference.
OK so I would say this but..... could you buy a blanking plate for all of £4 or so and see if that makes a difference? Up to you to remove it when you've cleaned /replaced the egr but at least you'll have an idea what's wrong (or not) for little money.

[agaafear]

My 1.8 C5 has a misfire/hesitation between 1700-2200rpm under partial/steady throttle. Does anyone have any idea what could cause this? It seems to happen mainly once warmed up, but isn't there if you 'floor' it..

I am having exactly the same problem - C5 1.8, 50K miles, runs fine except for this hesitation or jerking at about 2,000 (+/-200rpm). Particularly noticeable when driving on a light(ish) throttle in traffic, and it's occuring in all gears. I am now using the gears to avoid being around 2,000 rpm! The car has been serviced, new plugs, air filter, etc. I also put CatClean into it. Has always been used for short start/stop trips. Friend connected it to Lexia and "richness regulation intermittement" was the only fault message - not sure if there's a connection between these. Initially, I thought it was the throttle sticking - and I definitely sense that something is not responding as quickly as it should be.

I'd really appreciate any suggestions from others who have experienced this issue.

Many thanks!

[SaabC5]

Has anybody tried using a spray can of EGR cleaner up the the air intake pipe going to the EGR valve? Spray it up there without the engine running and let it sit for 20 mins, then start the engine and spray in very short bursts (long bursts will kill the engine).

[agaafear]

No! I wouldn't know an EGR valve if it was in front of my nose! Is this a paticularly expensive part? I guess cleaning it would potentially identify if it is the cause. I wonder did the OP get this sorted.

[agaafear]

€160 - €200 - depending on the brand - for an EGR.

[Smarty2]

I had this problem at 1500 rpm and after a software update shifted it to 2000 rpm! Only problem it gives is annoyance! A good dose of Archoil AR6400 to clean out the fuel system and a regular shot of AR6300 with a tank makes it a bit smoother, but not much.

[MadMalx]

No! I wouldn't know an EGR valve if it was in front of my nose! Is this a paticularly expensive part? I guess cleaning it would potentially identify if it is the cause. I wonder did the OP get this sorted.

Nope! Still living with this, although I find damp/cold weather worsens the problem so now thinking it must be electrical...

[agaafear]

Some electronic part of the coolant system was mentioned. I'm trying more fuel system cleaner! I notice it only happens when the car is a normal temp on temp gauge.