EGR and Intake DIY

Hello,
I can tell you from experience the EGR valve can be cleaned and reinstalled.regarding the intake manifold, why do you need to replace it? Depending on your mechanic skills,I believe it is doable if you have time and patience.

 

nice run! how is the ev range holding up?

 

Everything should be cleanable.

The EGR cooler is the toughest, and with your miles it's likely more carbon than steel, which is doubly tough: you may need to work a wire through the passages some, just to get cleaners in there. Some swear by medium pressure pressure washers, you could try that for starters.

My method (albeit at MUCH less miles) was to cork one end, fill with a concentrated Oxi-Clean solution (with hot tap water). Pour it in, prop it up, wait an hour, rinse and repeat. Took about 6 sessions thus to get it as-new clean.

The EGR valve and connector pipe to intake manifold are relatively easy. The valve being mostly aluminum, don't use Oxi, just brake cleaner, carb cleaner, something like that.

And the intake manifold needs cleaning as well, it's actually part of the EGR system. Pay particular attention to the small EGR passages, one at each intake port. They're roughly 6mm diameter. With your miles I'd replace all the pliable gasket on the intake manifold. Clean the throttle body too, while you're there. And can't stress enough: it is NOT necessary to disconnect throttle body coolant hoses for this.

Much more info, repair manual excerpts and links, in my signature.

Oh btw, I wouldn't even entertain having a dealership do this. And independent shops, especially if they're not familiar with it, are likely too expensive too.

Here's the "Oxi" of which I speak:

 

Which components are they proposing to change? There's an EGR cooler, valve, and pipe. And finally the intake manifold has EGR passages, from the pipe to the intake ports. I'd speculate:

1. They struggled with cleaning the cooler, didn't really get it cleared. Hopefully DID attempt to clean...
2. The valve was failing mechanically, and the problem persists.
3. They didn't clean the intake manifold, or did but missed the EGR passages.

Again, 250K miles is well into danger territory, I'd try a leak-down test first, verify (or disprove) the head gasket is still sealing.

Another trick, with the p0304 code (misfire on cylinder 4): move the coils/plugs around, say swap four with one, and see if the code changes or stays with cylinder 4. If the latter, that'd point to head gasket failure at cylinder 4.

 

Gasket masters has one how-to video for head gasket still up, that'll give you an idea what's involved:

 

Good video guide! We'll do the head gasket replacement on the Prius soon after we finished installing the brake pads, wheels and tires plus alignment on the truck and clear the garage.

 

The last link in my signature has a bunch of head gasket related excerpts from Repair Manual. If you can think of anything else ask in this thread and I’ll look.

 

If you need to have someone clean or replace your egr system, a head gasket job is far more challenging and includes removing the same egr and intake. Plus enough skill and experience to time the engine properly on the first try. Verification of warped block and head is needed and ideally the head is professionally rebuilt. In the end, nothing has reduced the excessive oil consumption which may quickly repeat the process. Which is the reason dealers only rebuild or replace these engines rather than a potentially disappointing hg job. Even Gasketmasters will stop and reaccess when they see damage.

 

If it is not broke don't fix it. At least in this case.