Gen 3 Input Damper Plate differences

I bought a used damper plate (I'm cheap like that) which has orange plugs/spacers within two opposing springs. (The red paint in the middle is just packing material) These plugs/spacers are similar in appearance to the black spacers found between the fuel rail and cylinder head. However, I don't see these on all such damper plates, although they seem to be on the "JDM" ones. Some of the plates have no spacers in the springs while others have black spacers in all four springs. Are these to protect the springs from excessive compression/breakage? Which models/years came with them? Are these spacers added because of recall or TSB?

 

What is with the damper plates with orange spacers in two opposite springs? these look like the black spacers used at the fuel rail but they're orange. i've seen some with them and some without them. don't know for sure which one this gen 3 has. were these changed or updated at some point?

 

Got the pieces out and here's a pic. One of four springs was pretty much intact but the other three are broken. I'd say I've recovered the majority of the debris and I ran a magnet around the places I could in the bottom of the transaxle housing. Most was recognizable as spring segments but probably also a pencil pea size collection of metal dust. Note also metal scrapes on the input damper. I think there was stuff grinding around in that area for awhile.

 

I'm thinking damper failure was due to misfire neglected for awhile. I'm doing a leak down test (hopefully today) to try to determine head gasket condition. If needed, will replace that and double check valves, etc. I do have an extra cylinder head lying around just in case. EGR I'm also going through but doubt it was cleaned before. Miles are 100K plus but don't have exact number as the motor is from a crashed Prius. I'm also thinking of doing leak down at the mid-point AND top-point of piston stroke to verify cylinder condition. Hoping to avoid engine swap but will do that if required.

 

I've actually done the head gasket in this car before with the engine in place. It would be a bit easier engine out, however. The prior operation went very well with one big exception. I noticed a cylinder with highly polished walls but had no idea why, although I asked far and wide. Turned out it was a bent piston rod which several thousand miles later went through the front of the engine block. This time I'm also going to measure piston height (along with the leak down test) which should both show a bent rod. (That's why I'm repeating leak down at the cylinder mid-point which would be expected to show higher leak down values at the defective piston.) When I did compression test on the last engine, the bent piston had higher compression than the other three.

 

Pictures

 

Yeah, one was all there but still bent. It had come out of its slot and is partly visible in one of the pics I posted. The small plastic spacer inside also has damage. The other three springs are fragged and the other spacer is smashed.

 

My Harbor Freight leak down tester doesn't seem to be working so I have improvised a test with my compressor. I've put my 3 gallon air tank at 100 psi and then observed the reduction in pressure to 50 psi. This takes between 1 min and 3 mins with the air exiting mostly from either intake or exhaust ports. I also have observed slack in the timing chain between the cam sprockets at some point, although the timing marks are correct on the chain and I've also repeatedly reversed the crankshaft rotation to try to get the tensioner to extend more. The small hook did release and I think the pin is maybe halfway extended and so I'm heading out to get a new tensioner. I don't think there should be slack in the chain between cam sprockets at any point.

 

I got the new Toyota tensioner but it didn't come with the metal shim/gasket. I'm thinking of using the old one and maybe a small amount of RTV on each side of it just to prevent oil leaks.

 

I was testing with piston at TDC on compression. I also believe it should work at and point within the next 180 degrees of crankshaft rotation where the piston would normally be following ignition and throughout the fuel burning process, allowing examination of various points of the cylinder wall. The crank bolt would obviously need to be securely held. (This of course assumes correct piston/valve timing and there might be some variation based on VVT, etc.) I eventually used an airline connected at 100PSI with piston at TDC on compression. At this point, I was able to hear compression lost either via intake, exhaust, or crankcase. Based on the time elapsed as pressure is reduced, I can get an idea of compression values relatively speaking, which sometimes as critical as the raw compression numbers. However, I don't think my results here were conclusive as the crank occasionally was off maybe 5 degrees and I wasn't able to hold it securely.

Anyway, I did an improvised compression test as I didn't have a way of rapidly turning the crankshaft. This is with the engine cold and turning the crankshaft bolt with a ratchet. (I'm still not sure whether the tensioner (new OEM) is completely extended but I can see that the latch is loose and I've turned the crank bolt in reverse to release it. The chain at some points in rotation has some slack in the links between the camshafts and I'd estimate that the tensioner is about halfway extended. These numbers are all substantially lower than normal compression test values due to the reduced speed of pistons. I can also say that except for a misfire and occasional exhaust spitting (unburned fuel from misfire?) the car ran well before I took the engine out. Oh, there was the awful clanking from the failing input damper.

Cylinder Avg. dry value Avg. wet value
1 40 50
2 44 50
3 46 50
4 40 51

From these values, I conclude:

1. Ignition timing is correct. This is verified by comparison of the timing chain links when lined up with the cam sprocket marks while the crank pulley is positioned at the "0" mark.
2. The fact that the wet values (5ml oil in each cylinder) are consistent tells me that the top end is good.
3. I think the lower end is good enough at this point and could improve with chemical cleaning or with more use.

I'd like to look at the cylinder walls but need better inspection camera lenses to do that.