EGR shake questions

So my 2011 CT200H has the shake and rattle at start up. Doesn't seem to be losing coolant, and the rattle/shake went away when I blocked off the EGR with the putty knife method. I pulled the intake manifold and while it's dirty, definitely not plugged in any of the passages. The pipe was clear as well, but dirty. I didn't have the time to remove the valve and cooler, planning to do that tomorrow.

After throwing it back together, the shake didn't go away after a couple seconds like before. My only thought about what could be different now is I took the plastic cap off of the magnet on the valve. Is there any way that I could have created an issue by just putting it back on and screwing it down? It seemed like a pretty simple mechanism. I did check that the valve moved freely by hand.

Any thoughts?

 

That sounds super frustrating man. I read another post where a guy had a similar issue, turns out the piece between the transmission and engine had rattled itself apart and destroyed the springs. So even though everything in the engine was working perfectly fine, it still rattled. Sounds like there are a ton of different issues that can cause the shake and rattle. Hopefully I'm lucky and the EGR cleaning fixes it. I'm hopeful because blocking off the system made the issue go away.

I was mostly confused because the issue remained after taking the manifold off for inspection and subsequently putting it back together, but it seems worse now. I rechecked that blocking the pipe made the rattle go away and it did, so it seems my issue in particular lies in the EGR system. I have a sneaking feeling that I caused some kind of issue by disassembling the EGR valve magnet. Maybe it's stuck fully open. I will find out tomorrow morning anyways.

 

Hey, thanks for replying. It's at 197k. I was able to confirm it had a "limited service campaign" completed in 2015 for the EGR at around 60k. I purchased it recently.

 

Fair point. I think I recognize your picture from replies in that thread. I imagine that guy's daughter drove it with an EGR shake for a while, he fixed that when he cleaned/replaced components, but damage had already been done at that point

 

I'll check on the head gasket. After cleaning out the clogged cooler the shake seems to be better. I am getting a p0401 now, I believe either the MAP sensor is dead/dirty, or the electronic portion of the valve is not opening the valve. Previously I believe it was stuck open. Thankfully in the CT200H the spark plugs can come out without removing the cowl. None of the plugs appeared to be steam cleaned, but one had some carbon deposits like that cylinder burns some oil.

Previously there was no p0401, only random misfire, cyl 1 misfire, cyl 2 misfire, and cyl 3 misfire. I don't think it was clogged, the cooler had some heavy deposits but some light could still be seen through it. My suspicion of the MAP comes from the fact I didn't remove it when spraying chemicals inside the manifold. I will drive it a bit this morning checking live data on the MAP and see if the readings it gives make any sense.

 

Perfectly quiet and smooth cold start this morning. Coolant level was lower than when I topped it off yesterday, but it may just have been from air pockets created when removing the EGR cooler. I'll continue keeping an eye on it. In the meantime I will figure out this P0401. I keep reading about Techstream EGR step testing, but I can't find a good place to download Techstream. Videos removed, malware, etc. Any ideas?

 

Back to shaking on start-up again this afternoon. I've done a couple hours of driving since that first startup this morning, coolant level does not appear to have dropped. MAP sensor performance seems fine. Baseline reading with engine off matches local barometric pressure to within a couple kPa, and it seems to respond normally to vacuum changes from throttle inputs when driving. I can see commanded EGR % on my scanner's live data, but I don't have functionality to actually test the system. Might look into grabbing one from a junkyard and testing. With electronics removed from the valve, it moves very freely back and forth.

 

After reading 15 pages of a thread about the ski jump, I now see that mine has a very nice groove cut into it. Obviously I dropped the spring from inside the valve into the belly pan with no hope of retrieval. I was disappointed to see that by the end of that 15 page thread, nobody had posted a picture of the ski jump on the revised EGR valve. Does anyone know if the rotor from a revised valve will fit in and work on the old version? I may eat have to eat my words on whether the coolant level has remained constant, the jury is still out on that one.

 

Thank you for the replies!

I made the valve and cooler spotless on Saturday. I don't believe the valve could be sticking from any kind of mechanical issue, it moves totally freely. I was able to retrieve the spring from the belly pan, and I created a new stopper on the inside of the magnet by drilling a hole and using epoxy to glue in a brass pin (nail) at the spot where the ski jump should be. Seems to have done the trick, I cleared the P0401 from the computer and it didn't come back from about 45 minutes of driving around.

Unfortunately the shake and rattle persisted the last time I cold started it. I'm going to remove the magnet from the valve and physically close it by hand. If it still rattles on start-up, I'm going to begin to believe the issue lies with the head gasket. Coolant level initially dropped after removal and cleaning of the valve/cooler, but seems stable at just below the "low" line for the last couple drives. Are there any other common causes of rattling at start-up? I don't have time to pull the head until summer, so this bottle of "Blue Devil" is likely to end up in the cooling system.

 

Yep, rattled as bad as ever when started just now with the EGR valve confirmed to be closed. I think I will run this head gasket sealer through it tomorrow and see if it will seal until Summer when I have time to address the problem properly. It will be interesting to see what the head gasket looks like after being sealed with this specific product. I see a lot of horror stories involving clogged coolant passages, radiators, etc. from the thicker types, but a decent number of positive outcomes with this one. I think my leak is small enough that there is a reasonable chance of success here.

 

I spoke to the Blue Devil support and they recommended against using the product since there isn't really any way to follow the instructions. I'm inclined to believe them when they say their product could cause harm. You have to pour it directly into the radiator slowly over the span of a minute or so while the coolant is circulating. No real way to do that on a Prius/CT200H. So I will have to figure out what else to do.

 

Yeah, I'm going to just go ahead and do the head gasket when I have time. It's a second car for us, so it can sit without negatively affecting us too much. I might experiment with taking off the coolant reservoir cap after driving to see if releasing the cooling system's pressure will prevent it from leaking into the cylinder as heavily.

Going to order this set from Rockauto, Victor Reinz 025402502. Anything obviously missing I should order along with it? Maybe a water pump?

Edit - Probably just going to order the OEM kit, as it will have the most recent revision of head gasket. Going to grab a water pump as well, this one is likely the original.