EGR/Intake Manifold Cleaning

So I haven't had a chance do the EGR/intake cleaning on my car yet but will get it done in the next 2 days, since owning the car (nearly 2 years now) have seen numerous YouTube videos, read about it here on the forums but just after a bit more info to ensure the process goes as smoothly as possible. Thankfully not experiencing any issues, but want to get it done as replaced the hybrid battery last week, so now the car needs to last as long as possible!

I already own a spare EGR pipe/valve/cooler set as well as spare intake manifold, bought this when I got the car. Planning to clean the spare EGR pipe and cooler (it isn't too dirty) today so I can have it ready for swapping it out. I think I will clean the cars original intake manifold and EGR valve rather than using the spare, as not sure if this spare valve operates at all, these are used spare parts not new. Got new rubber gaskets ready, got a new PCV valve and also got fresh new coolant ready for the system (haven't changed it yet under my ownership). Will also swap the spark plugs whilst at it.

My main queries are about what sort of cleaning chemicals everyone uses/what to stay away from etc.

• The EGR pipe should be easy enough to clean via brake/air intake (carb) cleaner along with bore brush?
• As there is an electrical component with the EGR valve, I'm assuming go gentle on that? Bore brush/wire brush and air intake (carb) cleaner only? Also how can I test the operation of it?
• For the EGR cooler I'm planning to soak it in oven cleaner, wash it out, repeat if necessary and then take it to a car wash for high pressure clean. Any advice here, leave it overnight? Few hours only? Neutralise the oven cleaner with vinegar?
• For the intake manifold, I have only seen people use brake/air intake (carb) cleaner, I am assuming harsher chemicals are not necessary? Also for the small port bores, how careful does one need to be cleaning them out, not to damage the plastic itself or is it pretty durable? Should one pressure wash this as well or is it not needed?

Appreciate any guidance.

Thanks.

 

THANKS! I had this in the back of my mind a few days ago but completely forgot. As I was also checking values for my MAF sensor (if it may need cleaning as well whilst I'm at it).

 

Perfect, I already have some oven cleaner on the way today from Amazon, so will start with that. We don't have oxi-clean here in the UK, although a comparative product seems to be Vanish Oxi Action here? Although ingredients wise it contains only about 30% Oxygen-based bleaching agents, oxi-clean is about 50-60%?

Is the active ingredient that helps breaks down the build up hydrogen peroxide or the combination of the washing powder with it? As I believe I have some hydrogen peroxide (liquid form) at home.

Thanks.

 

I'd be using a heat gun/hair dryer on low heat for an hour or more and leaving it outside to dry before hooking it back up.

I also have a spare damaged intake manifold that I have been thinking of cutting open just to actually see how much space there is internally and the "map" of the passages, always helps to visualise what you're dealing with.

 

Just to clarify is the sensor/name "Mode 6" on OBDII scanners? As I had a look yesterday but looked for "EGR" instead and don't think those are the correct ones (screenshot included). They mostly showed 0 whilst driving.

 

I cleaned the EGR cooler replacement that I had, I guess it wasn't that gunked up to begin with, it looked blocked visually. I literally blocked the holes and left oven cleaner (gel type) overnight, washed it out with a normal garden hose in the morning and it's sparkling clean. That's all it took. I don't have before photos unfortunately but will do the same with the one I take off my car and take some.

Also realised that the EGR cooler inside the "honeycombes" there are small spikes. I have read a lot about people putting things like coat hangers and the like into them to free them up, surely that isn't a good idea? As you're going to bend/damage those spikes - whatever they're for.

 

So managed to take the car apart yesterday, the process wasn't as bad as I expected, even the 'disposable' EGR cooler bolt wasn't too bad, I definitely won't be putting it back though. I don't believe the EGR cooler has ever been removed. 222,000 miles on the car.

The EGR cooler is absolutely clogged, I've done 2 rounds of oven cleaner on it (one overnight) and just garden hose washout and there is 0 through pass through it, guessing it's blocked in middle section, will give it a pressure wash and another round before just using the replacement as that's ready to go anyway, I guess I expected it to go as easy as the first one!

Surprisingly the intake manifold wasn't as bad, small ports weren't as gunked/blocked as I have seen on videos. That may have been replaced/cleaned at some stage or maybe didn't get as dirty as the EGR cooler was "blocked"?

Throttle body looked ok, gave it a clean as well.

I done a drain of the coolant beforehand, as will be replacing it anyway, however I was only able to get out around 5L? Is that normal or should I be getting more out i.e. closer to the 6L?

I also need some help with the EGR valve, as I took the two philips screws out to check the "plunger" works, it works well now, however wondering if I have put it back together properly. I twisted/turned the magnet all the way in before putting the top back on and then made sure it stays that way, the plunger is closed. If you just put the top back on without twisting the magnet the plunger remains open. Did I assemble it correctly?

 

Yeah I took out the nut first, then removed the stud for the lower EGR cooler bracket, cutting the bracket off. Left the two rear connected and gasket etc stayed in place.

 

Perfect, yeah I realised I could do that as tried it as well but for some reason in my mind it didn't seem "right"? As not sure how exactly it operates/reads or whatnot.

 

Put everything back together yesterday, what I realised is, the actual removal of the components and even EGR isn't the hardest, the hardest part is disconnecting and reconnecting the damn hoses. Took me way too long to manoeuvre the securing clips in their proper positions in tight spaces especially without a dedicated clip tool.

Replaced the PCV valve, old one seemed to clunk well but end was gunked in carbon.

What I forgot to mention was there was a bit of oil in intake manifold under the throttle body, nothing alarming I got out about 20ml of oil using a syringe, the MAP sensor on the intake manifold was also covered in oil. I ended up cleaning the MAP sensor using electrical contact cleaner spray (non-residue) it's safe for MAF sensors as well.

A further thing I noticed in the same region under throttle body inside the intake manifold is once cleaning and drying, a very thin sort of brownish film in areas, none of it near the actual top intake vents, assuming it occurs due to standing oil? This could be wiped off if you apply pressure with a microfibre cloth.