c900 cold turbo rattle?

Thread view:

Enable EMail Alerts

Start New Thread

Thread rating:

Ludwig - 08 Dec 2005 17:31 GMT

1990 c900, ~150k miles. For about a minute or less after a cold start,
I'm getting a tappety-sounding rattle, but only when the boost gets
into yellow. Of course, I try to take it easy on the throttle until
the engine has warmed up some, but I'm a little concerned that the
noise indicates an imminent wallet-lightening. Is the turbo maybe
taking a while to get properly lubed up? Could this be a sign of oil
coking in there? Or am I way off base and it's the timing chain or
something?

Thanks,
Ludwig

Reply to this Message

Dave Hinz - 08 Dec 2005 17:57 GMT

> 1990 c900, ~150k miles. For about a minute or less after a cold start,
> I'm getting a tappety-sounding rattle, but only when the boost gets
> into yellow.

Sounds like tappets from here.

> Of course, I try to take it easy on the throttle until
> the engine has warmed up some, but I'm a little concerned that the
> noise indicates an imminent wallet-lightening. Is the turbo maybe
> taking a while to get properly lubed up?

Doubtful.

> Could this be a sign of oil
> coking in there? Or am I way off base and it's the timing chain or
> something?

The timing chain sounds like a rattly-shuffly noise. Tappety sounding
noises are probably just...tappets... not fully pumped up until the oil
pressure gets up to full pressure inside them. Wouldn't hurt to have a
saab tech listen to it.

I can't think of any way for a timing chain noise to go away as the
engine warms up. A turbo oil problem would be more a squeal than a
tapping.

At least that's what it "sounds like" from here. If it's tappets, it's
not a problem unless you really _want to_ spend money to quiet it.

Dave Hinz

Reply to this Message

Malt_Hound - 09 Dec 2005 17:39 GMT

>>1990 c900, ~150k miles. For about a minute or less after a cold start,
>>I'm getting a tappety-sounding rattle, but only when the boost gets
[quoted text clipped - 26 lines]
>
> Dave Hinz

The OP may be describing "pinging" too.

Signature

-Fred W

Reply to this Message

es - 09 Dec 2005 01:51 GMT

> 1990 c900, ~150k miles. For about a minute or less after a cold start,
> I'm getting a tappety-sounding rattle, but only when the boost gets
> into yellow. Of course, I try to take it easy on the throttle until
> the engine has warmed up some, but I'm a little concerned that the
> noise indicates an imminent wallet-lightening.

if the turbo is bad one from a junkyard would only be like $150 and its
not that hard to install

just get a turbo with little shaft play and good seels

Reply to this Message

James Sweet - 09 Dec 2005 02:07 GMT

>>1990 c900, ~150k miles. For about a minute or less after a cold start,
>>I'm getting a tappety-sounding rattle, but only when the boost gets
[quoted text clipped - 6 lines]
>
> just get a turbo with little shaft play and good seels

That can be easier said than done, around here every turbo is gone in
the U-pull yards. I think the employees have first dibs on parts, either
that or some nutjobs wait around for the cars to come out on the lot and
pull the high value parts. Either way I'm sure the $25 turbos mostly end
up on ebay for significantly more.

Reply to this Message

joe schmoe - 09 Dec 2005 13:15 GMT

>>>1990 c900, ~150k miles. For about a minute or less after a cold start,
>>>I'm getting a tappety-sounding rattle, but only when the boost gets
[quoted text clipped - 12 lines]
>pull the high value parts. Either way I'm sure the $25 turbos mostly end
>up on ebay for significantly more.

Try checking a European Wrecker. The "Big Cars" like Saabs tend to
get disposed of well before they're due simply due, to the brutal
taxation on fuel. I saw a Loaded 97 Saab Turbo with 100K on it
certified and advertised by a dealer here in the UK for under $1,200
US. Parts at the breakers /wreckers are also quite cheap but the
shipping might cost a bit more. As for your own wrecker's yard, odds
are they've all been pulled off and are sitting on a shelf collecting
dust. Try asking at the counter.

Reply to this Message