EGR passage cleaning

04-12-2008, 05:46 PM
I've got a 95 Metro 1.0L with plugged EGR passages. I cleaned the valve 40k miles ago and all was well till I got another check engine light and code 51. This time I cleaned the valve and passages and still have a check engine light. I've tested all the components per the factory manual and they're all good but when I open the EGR valve with a vacuum pump with the engine idling, not even a bump. Keeps on running smooth. I cleaned the passages with a thin wire brish about 5 inches long, no help. Is there any special brush or tool that will get in there and clean it?


04-13-2008, 06:28 AM
Start the car with the EGR valve removed. You should have exhaust coming out of one hole and healthy vacuum on the other port. It's usually the port leading to the intake that's clogged the worst. I think that's because more cooling goes on there. Intake manifold and or throttle body has to come off to clean it well, you need to get to both ends of the passage.

04-13-2008, 04:14 PM
I would like to add to Woodie's excellent input.

The EGR passage starts at the exhaust manifold, travels through the head, through the intake manifold, to the EGR valve, and then dumps off at the end of the final passage at the back of the intake manifold.

Sometimes under extreme circumstances you must remove the exhaust manifold to clean it, and the passage that runs through the head more thoroughly.


P.S. Your work is not done until you can stall the engine at idle by manually opening the EGR valve.

04-13-2008, 05:31 PM
I made a device, out of a spring I bought at a local hardware store, that worms
its way thru those passages and cleans out the carbon.

I used a Vacuum Cleaner to suck the loosened carbon back out from the EGR ports.

You don't want carbon "chunks" getting to the valves and plugging them open!

I hope this helps you out....


04-13-2008, 09:44 PM
Doctorbill, I like the spring idea, thanks. I'll be trying it out as soon as I can.


04-13-2008, 09:58 PM
I like to use a flexible brush, then carb cleaner, then blow it out with a crompressor.

04-13-2008, 10:06 PM
Follow this link for more info on how to do it:

04-25-2008, 01:02 AM
I really appreciate all the input. I tried using a spring but it wouldn't go far enough. The blockage was on the exhaust side and finally I used a plastic coated piece of cable that I got at the local Ace hardware. I stripped the plastic off the last 1/4" and spread the cable wires apart to make a small brush. I used a portable drill to work it through the port and all is better now. Thanks for all the help.


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