- My model of MX-5 is: __NC2 2009 Sportech Roadster
- I’m based near: __Stirling
- I’m looking for technical help or recommendations on: __
Hi - anyone got any idea of the cost for a garage to replace a faulty EGR valve? It’s a ■■■■ job just can’t face doing it myself.
D
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Its around the £500 maybe more now with new valve assembly and labour. Many (myself included) have changed out the electric stepper motor which is usually the culprit not the valve itself. With patience and a few basic tools it can be done without too much difficulty by the home mechanic.
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You might as well get it removed and flashed by bbr or someone for about £100 more. Will sharpen throttle and make it a bit more responsive.
Thanks for that
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Am I missing something here??? It’s the EGR the thread is about
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Yes, they simply deactivate it and the re flash stops the car looking for it. Read the text on the website you will see it towards the bottom. De activating it reduces the air temperature and gives you a few more horses as a result. I understand It’s more effective than changing the airbox that is more about induction noise.
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Reminds me of the Mondeo Mk3 2.2TDCI I used to have. They were a *** for getting through EGR valves but luckily easy to replace. In the end I took one apart and realised that water was getting in and rusting. This stopped the cogs from opening and closing the valve. Design fault. So on the new one I drilled a drain hole in the bottom and never had a problem after that.
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So the EGR is a fuel saving device, making the fuel mix weaker by recycling exhaust gases. Sounds a bit daft to me. Surely there’s a simpler way.
So is it illegal or not - an MOT fail or not?
If an EGR delete and remap for around £500 gives you 8 bhp (say 5%) will that mean you use 5% more fuel?
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Egr is an environmental device. It is re burning left over exhaust gases to reduce emissions further. Speak to bbr yourself but I understand from most that have had it done that the ecu flash improves economy a tiny amount rather than reducing it. This may however be some way of having a personal excuse for getting it done. It’s on my list when I feel I have got the most out of the car as it is.
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That’s not really what EGR does. It mixes exhaust gases into the inlet while cruising and that dilutes the proportion of oxygen in the intake, so the the amount of fuel added is reduced too. The result is you actually cruise with the throttle a bit wider open to get the same power as you would without EGR and that reduces pumping losses meaning the engine runs more efficiently, saving fuel. The other effect is it reduces cylinder temperatures which decreases the amount of NOx pollution created.
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Sounds pretty much the same to me, just more technical. Most people are interested in the end result which is to help with lowering emissions. My time spent cruising in my sports car is minimal so I imagine it’s closed most of the time anyway.
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In diesel cars the main result is lowering emissions, in petrol cars you get better fuel economy (and lower emissions too).
And ‘cruising’ doesn’t mean dawdling it just means the time you spend driving while not accelerating.
Whats the actual issue with the EGR valve ?
There’s a known issue where the electrical motor on the top fails, the valve its-self may be OK.
Its possible to replace just the motor if youre handy with spanners etc.
Probably not the easiest of tasks given its location, but achievable within about an hour.
Just to note, the EGR valve is almost the same one as fitted to the Mondeo.
An eBay special is much cheaper for the Mondeo, than it is for the MX5.
Buy a Mondeo one and swap just the motor over.
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Hi Keat63,
Thanks for this.
The problem with the EGR is the warning light which isn’t switching off. The car is actually running ok.
Dave
Mine went about 3 years ago. I dont recall the OBD code.
I bought a mondeo valve and swapped just the stepper motor.
While the motor is off, you can check if the valve moves. If it does, then chances are its the motor which failed.
There have been a few reports over the years on here.
When i did mine, the valve was about £20 for a mondeo and £150 for the mx5, so its worth a punt.
My car also seemed to be running right.
Here are the Diagnostics for the EGR Valve courtesy of Mellens. In the majority of cases it is the motor that is the problem but you may be one of the exceptions. However I think by the time you have managed to access the connections it may be quicker to remove the stepper motor and test it off the vehicle, best of luck.
I believe if you change the whole valve, it requires a coolant drain, so going for the stepper change first, was my preferred route.
To perform the job, you have to remove the wiper arms and scuttle panel. The plastic scuttle panel screw covers will probably snap taking them out, but you can get these from mx5 parts for a few quid.
At the rear of the engine on the bulkhead is a steel inspection/access cover, which you have to remove.
And possibly remove the strut brace (if yours has one)
Then remove the wiper motor/assembly. It’s possible to change the stepper motor without removing the wiper motor, but it’s only 3 bolts and makes the job so much easier.
If I recall, there’s also a pipe on the bulkhead which needs moving out of the way.
You should then see the EGR bolted on the rear of the engine.
You’ll need an extra long magnetic screwdriver to get the four stepper screws out.
They will be tight, so you may need to shock them with an old screwdriver and hammer to crack them off.
The stepper then just lifts off.
At this point you can operate the valve, I can’t recall if it rotates or pushes, but If the valve moves freely, then it’s probably OK.
Because of where it is, you’ll get back ache, and may find it easier with the bonnet down once you’ve gained access.
Before you resemble everything, put a patch of bitumen flash band over the scuttle grommets.
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I had mine replaced (NC3) by a small local garage with motor sport experience. The genuine Mazda part was well over £200 (I can’t remember how much). The owner was really cross because he’d never fitted one before and quoted for a couple of hours work. But it took him 5 because the valve was tucked up very tightly behind the engine and was extremely inaccessible. So I don’t know why folks are saying it’s an easy job. It works though and the car runs fine…
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The valve is a pig of a job, requiring special short angled spanners etc, very difficult to get to, but the stepper motor is quite easily accessible and can be completed in about an hour.
Another eason why I opted to go down this route first.
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