how a $1 part destroyed my SR

Post by **hurddawg** » Fri Oct 10, 2003 9:30 pm

I just swapped in SR last Sunday. It is now dead.

I'm possibly jumping to conclusions on this but I'm pretty sure of it, read the story...

I was goofing around with a friend of mine on the freeway and we had some fun (nothing stupid). We get off the freeway and the motor sounded like utter crap. It had a very loud sound like a HLA had failed, TAP TAP TAP TAP. I decided it was time to go home. I was considering at the time to leave the car (empty parking lot)where it was, but it was not a good part of town at all (DT Tacoma) so I decided to drive it home. We also didn't have a Cellphone with us, smart huh? I never had the thought that the following would happen...

About 1/2 way home while on the freeway at 60mph. I hear this light clunk adn the engine dies. I coasted to the side and tried to restart it. Sounds as if it has no compression on any cylinder, it was fast cranking and whizzy. I was praying to the car gods. I was hoping it was something like multiple rocker arm failure or soemthing, but it was not meant to be...

$136 later (towed), I pulled the valve cover and every thing looked great, the cams, timing chain and rocker arms. I checked the side of the engine to make sure I didn't blow out a rod. It was good, I had plenty of oil and coolant. Just as I was about to give up I noticed that the exhaust cam dowel pin was broken, it was now in a "s" shape-ish. The CAS drive gear is also slightly smunched too. I looked at the valve springs and it looks like all the valves (intake and exhaust) are closed (or about to be). You could also visually see that the CAS drive gear on the Cam was moved (shiny metal areas on the cam sproket).

So a $1 part killed my SR.

I have a spare exhaust cam from my g20 that I'll plop in the 240 tomorrow night and do a compression check to see if the valves are really bent. I would be one lucky SOB if there weren't.

so thats my sad story

I'll have a pic tomorrow

Post by **SpeedRacer1** » Fri Oct 10, 2003 9:30 pm

So the dowel fell off and you think the exhaust cam began to spin freely of the sprocket?

Post by **hurddawg** » Fri Oct 10, 2003 9:30 pm

dowel didn't fall off. The cam slipped, you can crank over by hand and the exhaust cam still turns, I'll get more detailed pics tonight so it'll be easier to understand.

Post by **SpeedRacer1** » Fri Oct 10, 2003 9:30 pm

Well I dont believe the valves would have impacted with the pistons because of the lower compression, so you may have dodged a bullet. Though if your not sure, I still have other parts if you need them.

Post by **UsedToOwn240SX** » Fri Oct 10, 2003 9:30 pm

Oh man, I'm sorry to hear that. Get a new head and you're set to go I suppose. What $1 part that fails? Pictures please so we understand.

Post by **hurddawg** » Fri Oct 10, 2003 9:30 pm

I'll go get some pics in a minute, but the $1 part was the dowel. It did infact break, but it is still wedged within the CAS drive gear. So as far as I know right now, there are not chunks of metal in my oil pan.

I also re-read my post to clarify a few points...

-- the tapping sound was definately from the top end near the front of the VC. We had a screwdriver handy so thats where we pin pointed the tap. Also the reason why I pulled the VC off first when I got home.

--The engine is now just past TDC on #1, so when refering to 'all the valves are closed' I'm refering to cyl #1 only.

I'll be right back

Post by **PalmerWMD** » Fri Oct 10, 2003 9:30 pm

Fred...

Post by **hurddawg** » Fri Oct 10, 2003 9:30 pm

here are the pics.

as you can see the exhaust cam is advanced a link or two at TDC. You can see the carnage of the pin in the other photos.

well the good news is that by hand cranking a few times I can tell there is some compression, so valves might be ok. In that case all I'll need is a new exhaust cam.

Maybe when the mixture ignites it blows out the exhaust right away because the advanced cam??

Post by **ItzGenX** » Fri Oct 10, 2003 9:30 pm

By counting the number or rollers on your chain from mark to mark, the timing hasn't physically jumped on the chain at all. It is 20 pins/rollers between marks. By the FSM, your timing is on par at TDC (in@10 o' clock, out@ 1230)--exhaust dowel pin should be almost 12 o' clock square at TDC--.

In stead of lining up my chain to my marks, I find it easier to do the clock+counting rollers method to do my cam timing, works fine. My chain's actual marks never touch any mating marks to begin with that's why.

Your problem seems to be the broken dowel pin (obviously) and maybe a prob with the cas/ignition timing that is causing such a big problem. Seems your exhaust valve timing may have been advanced/retarted like 5 degrees due to broken pin.

Post by **RobDET** » Fri Oct 10, 2003 9:30 pm

Yah everyones timing marks look like that when it's set right. Be careful when you put in the new stuff. It doesn't look like you killed anything...

You will ride again!

Post by **hurddawg** » Fri Oct 10, 2003 9:30 pm

For some reason the ehxaust cam mark looks further off than it should have been. I cant see how the chained skipped maybe I'm just imagining things.

I guess one thing of note is that I assembled the engine, I bought it "assembly required" type of thing. The block and head were seperated. Maybe I did something?

My dad brought up a good point, though I need to find out what may have caused it. The tapping seems like an entirely different problem, but seems kinda odd that it had gotten louder just before the engine died. I also used a torque wrench to torque down the cam bolt.

It is also just plain wierd that there was so much force that just busted that pin. Clearly this is not a common problem. Hate to fix it to happen all over again.

Post by **SpeedRacer1** » Fri Oct 10, 2003 9:30 pm

Hydraulic lash adjustors? I know that we removed them on that engine at one time and did not reintsall them properly (Bleeding them). So unless you redid them properly, they should have been making some sounds.

There should be 20 rollers between the two mating marks. If you really needs help redoing something let me know and I can meet up with you.

Post by **ImportIntelligence** » Fri Oct 10, 2003 9:30 pm

From the looks of the pictures, the CAS gear was rubbing pretty hard on the cam gear. Unless the cam gear is off center or lobed then it's very hard to get wear marks like those. Do the marks oin the cam gear go all the way around?

Post by **hurddawg** » Fri Oct 10, 2003 9:30 pm

SpeedRacer1 wrote:Hydraulic lash adjustors? I know that we removed them on that engine at one time and did not reintsall them properly (Bleeding them). So unless you redid them properly, they should have been making some sounds.

There should be 20 rollers between the two mating marks. If you really needs help redoing something let me know and I can meet up with you.

that may explain the tapping I guess, I removed them too but I put them in a bucket of clean oil, so I thought they were ok or one failed. anyway, I should be fine with the timing. I just haven't done anything because I have this wicked cold right now.

Post by **hurddawg** » Fri Oct 10, 2003 9:30 pm

ImportIntelligence wrote:From the looks of the pictures, the CAS gear was rubbing pretty hard on the cam gear. Unless the cam gear is off center or lobed then it's very hard to get wear marks like those. Do the marks oin the cam gear go all the way around?

I noticed that too. and Yes the marks are all the way around. That is not as bad as the CAS' gear though it looks a bit worse. I'm hoping that the CAS drive gear is just off center...

Post by **Oneor1** » Fri Oct 10, 2003 9:30 pm

Sounds all too familiar.... Same thing happend with my CA18....noticed a knocking sound but it kinda went away..... then im just cruising along and then.....nothing....... just died....i dropped it into 3rd and boooom...loud *** back fire....i coasted to the side of the road..pulled my CAS off right away and saw the pin had broken off.... i got some Ca16 cams and it runs fine now... has a tiny miss but it could just be a tooth or so off on the timing belt.... anyways... good luck.... i dont think you messed it up all too much...hopefully not

-Rick

Post by **RobDET** » Fri Oct 10, 2003 9:30 pm

CA's have belts? one more point for the SR

JK!

Post by **Movingviolation240** » Fri Oct 10, 2003 9:30 pm

I killed a CA (sorta) in about the same way. Had the cam come appart (just the key up front) . Luckly I had a spare cam in the trunk and got the thing running right away (with a thicker head gasket it was a non interference motor).

Paul

Post by **SpeedRacer1** » Fri Oct 10, 2003 9:30 pm

hurddawg wrote:that may explain the tapping I guess, I removed them too but I put them in a bucket of clean oil, so I thought they were ok or one failed. anyway, I should be fine with the timing. I just haven't done anything because I have this wicked cold right now.

You cannot just put them in oil. You actually have to bleed them by pumping them with a thin object, when they are no longer able to be pumped they are ready. That would definately explain the tapping sound, however I believe that is independant of why the engine stopped running. Even if unbled, the lash adjustors should only cause an unpleasant noise, not blow anything up (according to the FSM)

Post by **hurddawg** » Fri Oct 10, 2003 9:30 pm

SpeedRacer1 wrote:You cannot just put them in oil. You actually have to bleed them by pumping them with a thin object, when they are no longer able to be pumped they are ready. That would definately explain the tapping sound, however I believe that is independant of why the engine stopped running. Even if unbled, the lash adjustors should only cause an unpleasant noise, not blow anything up (according to the FSM)

aha! but you gotta remember I didn't know that you guys removed them.

In the fsm it says that if you remove the HLAs put them in a bucket of oil or make sure that they stand up straight. So when removing them, bleeding them didn't cross my mind. My only reason to remove them was to clean out the old oil.

It was just really odd that the HLas suddenly got really loud it was just a tap-tap-tap then the TAP-TAP-TAP (after oh 50 miles). I guess what I'm getting at is whether the oil pump is ok (HT said it can be an indication). From experience, HLA just don't suddenly get loud unless they fail internally or loss of oil pressure...

Website · Post by **quiksilvia** » Fri Oct 10, 2003 9:30 pm

i just replaced my head and i have rocker arms, hla's (if even shipable) cams, chain, gears, all that crap-let me know if u need it-or did u say u already bought one...

Post by **SpeedRacer1** » Fri Oct 10, 2003 9:30 pm

Doesnt matter quik, I have all that stuff too and I live a short drive away :P I win.

It doesnt matter about if they are removed and immediately placed in oil, every time they are removed they need to be bled. The easiest test is to pump one after removing it, if it isnt stiff, its a safe bet they all need to be bled. If it is the oil pump, I have an extra one of those too.

Website · Post by **quiksilvia** » Fri Oct 10, 2003 9:30 pm

o yea.....well.......er.....im cooler.....yea

how a $1 part destroyed my SR

how a $1 part destroyed my SR

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