'92 240sx Convertible - Some timing chain questions.

[09quickly]

***I also posted this in the KA engines forum. Pictures did not post, I will try again tonite. I have been slowly pulling apart my KA24DE, 165,000 + miles, among many other things, it had the rattle at the front of the engine. I think the head has been worked on before, the cams seem to show very little wear. Also, the valve cover gasket (rubber) stayed intact when I pulled the cover. I found what I hope is part of the top chain guide, jammed down in between the iron of the head and the valves for cylinder #1. The other part was resting on the gears for the distributor, and would not come out until I pulled the distributor. Hopefully, that was the source of the rattlle. It has a serious oil leak up front, and has apparently been blowing back on the engine for quite some time. Alot of grease and goo. 3 main questions, with many side questions also.

1 - I set the #1 cylinder at TDC on the compression stroke (both valves closed) and pulled the distributor. Not too bad. In loosening the crank bolt, I noticed alot of play in the top chain gears, even though I put a scewdriver through the gear into the valve tray to hold everything in place. Still movement on the lower crank (1" - 2") before everything grabbed and I was able to loosen the crank bolt. Is that much movement something to be concerned about? I hope it didn't mess with distributor placement.

2 - water hose that feeds from port on timing cover (right side) toward back of engine. Is there an easy way to access the hose clamp to loosen it for removal?? That thing is a bi__h! Cover will not break loose from the block, I am hoping that is it.

3 - In one of the posted pictures, I am pointing at another component that bolts to the timing chain cover, also on the right-hand side of the engine (left when I am working on it) . Unfortunately, it is covered with oil, but, what is it? It also has what appears to be a water hose leading to the rear of the engine.

Any suggestions, advice, give a shout. I am done for the weekend, hope to work on it again next weekend.

[180fan]

1. No2. Long screwdriver3. this one might need a picture to clarify

With the timing chain, loosen the cam towers. This will close all the valves and you can rotate the crank without the pistons crashing into the valves. Get the chains on and lined up properly then with the slack in the chains (tensioners not applied yet) tighten down the cams at their TDC positions. If you've lined up the links like the way they should, you'll have no problems. Pull the pins on the tensioners and you're set.

[09quickly]

Thanks for the reply. I hate to show my ignorance, but I cannot figure out how to post photos to this thing. The icons mentioned in the picture posting tutorial do not show up at the top of my screens. Click and drag photos? forget it. Attach file? Same thing.

[180fan]

It's under the file attachment. Click the "browse" button and point it to the file you want to upload.

[09quickly]

Took another stab at posting the pics. Browse, file found, choose pic(s), move to space next to browse, hit post, after a short wait, tells me file cannot be larger than 500000 bytes, go back. Same as last time. Do I need to do something else to register on this site for pics to load? I am obviously computer challenged, but I have attached photos to e-mails before.

[09quickly]

In the garage right now, trying to get the timing chain cover off. Approx. 1/2" of space showing all around the T/C cover, but will not budge any further. Is there something else in the front crank seal area that needs to be loosened?? Bolt is out, key-way is out, 6 oil pan bolts are out. I can see the seal(?) where it SHOULD slide over another piece of round metal with two flat sides to it. Feels like something inside the cover is holding it on.

[180fan]

You need to drop the oil pan. It's a real pain in the butt. If you haven't replaced the engine mounts recently, you'll probably need a hoist.

[09quickly]

That's fine. One of the many things wrong with this car when I bought it was a good-size crease in the front of the oil pan, so I ordered one and have it handy. I was told that as opposed to a hoist, I could rig something across the shock towers to suspend the engine, while I drop the suspension parts necessary to get to the pan. I was hoping for a hoist hook of some type on the engine, but I don't see one in the usual places. Any suggestions??

[Indy]

I don't know if it is right or not, but I just put a jackstand on my transmission to hold everything up while I dropped the suspension.

[180fan]

Dropping the front is also a good option, just I'd be terrified of the engine shifting on a jackstand or the bolts at the transmission warping. You could rig up something across the strut towers to suspend the engine, but haven't used anything like that yet.

[09quickly]

Another stab at pictures. My AOL has gone T.U. I read in another thread about the possibility of loosening motor mounts, jacking up the engine with the oil pan itself, put blocks of wood? something else in place for motor mount to rest on when engine is lowered, do the pan. I wonder how much space is necessary to clear the old oil pan and put a new one in while contending with RTV?

[180fan]

the oil pan is one piece IIRC. You'll still need a way to keep the bugger up while you're cleaning the old gasket up and getting the new gasket on for the oil pan.

[09quickly]

I was able to work on the car a little this afternoon. loosened power steering lines, and bolt securing steering knuckle to the p/s assembly. Passenger side motor mount bolt was a snap. Driver's side, started rounding the head on the nut. Hope to buy a tool to get that sucker off tomorrow. As far as suspending the engine, I am toying with the idea of using a thick gauge cable, still easy enough to snake through the A/C bracket on the driver's side, and the alternator bracket (alternator removed) on the passenger side. Secure both to either a 2X4 across the shock towers, or a metal pole I have left over from the trampoline (finally, that thing comes in handy!) Will let you know. Also- I removed my interior, looking to replace carpet and have front seats redone. I have been looking at stockinteriors.com for the carpet. Looks like a decent match. Any thoughts on a betrer place to look?

[180fan]

you can suspend the engine via the manifolds. Good luck with the motor mount nuts. Those things suck, I had to cut both passenger and driver side when I was replacing them.

[09quickly]

I bought some sockets designed specifically for removing rounded nuts and bolts from Sears, worked like a charm. Soaked the nut in PB Blaster two days ago, and the more I cranked on the problem nut with the breaker bar, the more the socket dug in. No slipping at all. Nut is ruined, but who cares! I bought a small set of 5 sockets, 1/2 inch drive, fit metric and standard, for $20. These things are slick!

[09quickly]

I hope to do my oil pan this weekend, will keep you posted. Another question: When I removed the top timing chain cover, I found what appears to be the one piece head gasket that extends past the head to the timing chain cover assembly. This gasket sustained some damage when I removed the upper cover (slight bend, pieces of gasket stuck to the cover). Am I screwed, or can re-use this thing? The head was not touched at all. If it is not re-usable, what are my options?

[180fan]

You can try sealing it back up with some RTV. I know exactly what you're talking about, there's the little U thing that's comin from the headgasket and meets up between the front cover and the cover for the chain up top. I just slapped on some rtv after cleaning off the oil on my buddies. works fine.

[09quickly]

Finished dropping all of the front suspension parts this weekend, oil pan is off!! Found many front end parts where the bushings had disintegrated, so will be replacing them too. Cleaned timing chain covers, everything else that will be reused that was caked in grease and crud. That took a good part of the afternoon, and that doesn't include the frame and suspension parts still on the car. Now to order the new parts (front seal, timing chain, guides, water pump, upper and lower radiator hoses, thermostat, $$$$$!!) *****QUESTION: I have read in other threads that the timing chain itself never really goes bad, only the tensioners and guides. If this is the case, do I really need to replace the chain at this time if there is no visual damage? Looseness in the chain should be corrected by the tensioners, correct? My concern is removing the old chain, and running into problems with the whole "1 tooth or 1 link off" headache if I put it all back together and it won't start.
Modified by 09quickly at 9:34 AM 4/10/2006

[09quickly]

****New question at the bottom of this post *****QUESTION: I have read in other threads that the timing chain itself never really goes bad, only the tensioners and guides. If this is the case, do I really need to replace the chain at this time if there is no visual damage? Looseness in the chain should be corrected by the tensioners, correct? My concern is removing the old chain, and running into problems with the whole "1 tooth or 1 link off" headache if I put it all back together and it won't start.

[09quickly]

Bump.

[180fan]

You don't usually have to replace the chain. You can check the links for wear and cracking, if you find they've got wear or cracks, replace the chain. Now if you're too lazy to check over the 50+ links on the two chains you've got, I'd say just cough up the extra cash and get a new chain and have one less thing to worry about later. The people that get one tooth or 12 teeth off are the ones that aren't careful enough with the install and go willy nilly with the punch marks. Follow the punchmarks and count the number of links. Crucial to being uber-anal-mechanic that wants as little downtime as possible. Also very good for eliminating those annoying headaches from doing a half arsed job on something as important as a timing chain.

[09quickly]

Thanks, I will check those chains with a fine-toothed comb. As I said earlier, it looks like the top half has been worked on before, judging from the "freshness?" of the valve cover gasket, little to no noticeable wear on the cam lobes, etc. I could be wrong. What you brought up is exactly my dilemma. Having never done a timing chain of this type before, It is a little intimidating. I am not real comfortable with how much slack was in the cam gear and crank when I manually moved #1 piston to TDC. I hope the distributor gear setting is still where it needs to be.

[180fan]

Don't sweat it. Just make sure you cover your tracks by double checking the punchmarks and the colored links and count the number of links between the punchmarks to make sure you've lined up the chain properly and you'll be fine man. Seriously.

[09quickly]

I have been working on the convertible here and there, I have been cleaning parts, ordering some new ones from Pinnacle Nissan, picked up my seats, carpet came in, just waiting for parts to arrive and hopefully I can reverse the whole process. Earlier in this thread, I asked about a component that was bolted to the timing chain cover, but I couldn't figure out what it was.....it is the PCV connection box. I have no idea how you get to that thing in a "simple, preventive maintenance" Saturday. It was a b--ch with half the engine removed!! Got a picture to load finally, this is the top chain guide that was lying in the head, between the camshaft and the iron. Some wear marks on the head itself, also some wear marks on the distributor shaft (other half of chain guide made it down there), but no apparent damage to the business end of anything. I will try for more pictures.

[09quickly]

Parts are in from Pinnacle Nissan, hope to start reversing the process. QUESTION: removed the oil pump gear cover to get access to the front crank seal. I notice on the oil pump gear assembly, there are two dots or indentations, one on the gear, one on the lop-sided piece it fits into. Do I need to align these marks in any particular way when I re-assemble? Both marks at 12 O'Clock? One at six, one at twelve?

[NISTECH]

line them up, that puts the distributor end at tdc.