Chain Rattle at Start-Up
 

I know this is a very common ailment, and if my Boxster sits for more than a week, I'll get the 1 second chain rattle at first start. I don't know if/when it should be addressed, as the car has less than 40K miles. I do have a quick question related to this however.

If I quickly bump the engine over a few times without starting it (not sure if that will work or not), will that pressurize the system enough to mitigate/eliminate the rattle at start-up?

A little rattle at cold start up is very common and usually is not an issue. Solving the problem the way you are describing might just cause another issue like a screwed up starter or bendix gear requiring a repair or replace. And you'd still have the start up rattle.

Bugs me also. I give the Boxster a little shove, it rolls out of the garage fifteen feet. Start it up, no rattle.

The oil pump has to generate oil pressure to pump up the chain tensioners. That means that the oil pup must spin quickly for at least a second or so (in other words, the engine must run to do this), so just bumping the starter isn't going to accomplish anything.

Upgrade your OPRV - it helps retain oil pressure at start up.

Replace your tensioners.

What oil is in there? Switch to 10/40 or 15/50.

See what happens.

:cheers:

I routinely crank the engine on the starter with the fuel pump fuses pulled after a long sleep. No affect on the starter as yet. I can't see oil pressure build as I have no dash mounted analog gauge. I would think the oil would circulate on the starter and some pressure developed.

I don't believe I have ever managed to stave of chain rattle on the starter

Yes! PRV! This has been on the list for a while....it's a 997 part number I believe.

Whats OPRV mean,.. I changed 1 out of the 3 tensioners I did the IMS one, the other bottom one was still strong and I didnt get the top one yet..plus I went to 20-50.And I still have the rattle,andits getting to be on every start up now ??

Uhh..oil pressure relief valve.??

I bought a 03 996 with 67K well cared for miles. Car had been driven only about 5K miles in the previous 5 years prior to purchase. I would get some chatter at cold start and was concerned about how I would solve it. I did 2 things....

A few hundred miles prior to an oil change, I added Marvel Mystery oil to the the car....maybe a pint or so, and drove the car for a few hours.

Also did the OPRV while I was changing the oil.

I haven't heard the rattle since. Been about a year.

Thanks gang...Is the OPRV an easy replacement? I saw above it's a 997 part number. I assume this is an "upgraded" part?

It's very, very easy. You can do it in 10 minutes... likely less.

I installed that upgraded part a few years ago... didn't stop my rattle. I also didn't install new tensioners.

I'm going to try the MMO technique before the next oil change... see if that doesn't help.

Keep us posted on your install of the OPRV. :cheers:

Would the top ( AC ) tensioner have anything to do with rattle thats the only one I did NOT change,.? Thanks Frank

For what it is worth I had a similar issue several years ago (4 or 5 probably). Was a combination of what sounded like chain rattle and/or lifter tick. After reading all of the "snake oil" comments concerning MMO, I came across an old reply from Jake Raby who said he had "...saved many an engine using MMO." At that point I decided to start a regimen that I have stuck with to this day for each oil change. Every 3,000 miles I add 4 ounces of MMO to a full tank of gas. I then drain an equal amount of oil to the remaining amount of MMO and add the MMO to the oil. I drive the car for about 300 miles and do a complete oil change with Motul. I also get a Blackstone report with each change which I will be glad to share with anyone interested but they are amazed at my numbers. Most importantly, NO chain rattle or lifter tick in years after following this process. It may all be worthless other than in my head but going on 6+ years without a single issue or problem. It's been one of the most reliable cars I have owned and I was a Toyota/Honda zealot.

What is the "remaining amount of MMO"? In ounces, please. Thanks! :cheers:

I buy a one quart bottle so minus the 4 ounces in the gas tank means I put 28 ounces in the oil. To determine I have released enough oil I marked an old drain pan with a mark on the side equating to 28 ounces. I then crack the drainplug and unscrew it just enough to get a good stream and fill the drain pan to that mark. Just be careful you unscrew the plug a little at a time because, as you guys know, this oil comes out like a geyser. Good luck...