Rattle at start up?

[greenrob]

Hello all hope someone can help me out. I have a 98 Boxster with tiptronic, on start-up I hear a brief rattle coming from what seems to be the lower engine. It only last for a few seconds. Seems to be an oil issue, should I be worried? Or is this a normal sound? Thx in advance!

[greerj1]

The rattle is the lifters before they fill up with oil. Fairly normal with a higher mileage flat six.

Jim Greer

[greenrob]

Thx for the reply. Does that mean I have nothing to worry about and is there a fix?

[timbo]

Hi, what grade oil are you using? is it worse in the winter? whats the mileage of the engine? a thicker oil takes a little longer to get to the lifters.

[greenrob]

I am using 0-w40 Mobil. 1 Car has about 55k. Don`t recall hearing it in the winter.

Thx for your reply

[Jake Raby]

Hydraulic chain tensioners.. Not the lifters.

When the tensioners bleed down lots of slack occurs in the timing chains. This can cause the engine to jump time.

Change all 3 tensioners, B1, B2 and the IMS drive chain and it'll go away.

[timbo]

Depends which side of the pond you're from. here they're called tappets, hydraulic tappets, some times they bleed a little oil, thought they were called lifters where you are. Tensioners a different animal altogether.

[Jake Raby]

Lifters only make slight tapping noises and they generally do not make a notable noise at start up more than at idle..

Lots of people have changed lifters only to find thats not the root of the issue and that the chain tensioners are the issue.

These engines do have lifter issues, significant lifter issues, but most are masked so well that the Owner never knows that 90%+ of the lifters are actually bad.

[suburban99]

By chain tensioners, do you mean the varia-cam tensioners?

If so can they be rebuilt, or do they need to be replaced?

[Jake Raby]

No, I mean the 3 main chain tensioners that maintain the main drive chain tension.

[timbo]

Lifters only make slight tapping noises and they generally do not make a notable noise at start up more than at idle..

Lots of people have changed lifters only to find thats not the root of the issue and that the chain tensioners are the issue.

These engines do have lifter issues, significant lifter issues, but most are masked so well that the Owner never knows that 90%+ of the lifters are actually bad.

Well I suppose we've all got different experiences, I've known the odd lifter rattle at start up and then go silent. I don't think Greenrob has too much to worry about if its a brief rattle and not too loud.

[suburban99]

No, I mean the 3 main chain tensioners that maintain the main drive chain tension.

Ok, can they be rebuilt or do they need to be replaced? Part number(s) would be great if possible.

I am taking my car off the road up here in November and will be working over the Winter on it...

[Blue-S]

Hydraulic chain tensioners.. Not the lifters.

When the tensioners bleed down lots of slack occurs in the timing chains. This can cause the engine to jump time.

Change all 3 tensioners, B1, B2 and the IMS drive chain and it'll go away.

Are any Porsche special tools required to change the three tensioners? I understand that some special tools are necessary when timing the cams after the heads have been off.