"Growling" When Cold

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April-1st-2005 | 05:20 PM

mitchman

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"Growling" When Cold

My 2003 DX (2.0L) engine seems to "growl" more when it's not warmed up. It goes away as soon as the temp starts to come up.

It's not a bad sound...the engine is just noiser.

I'm hoping it will go away once I switch to synthetic motor oil.

Anyone else notice this?

April-1st-2005 | 06:18 PM

Matty Mooling

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From: Elizabethtown, PA

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Quote:

01-004/03 2001-2003 Protege, 2002-2003 Protege5 - RATTLING NOISE AT 1000-3000 RPM COLD ENGINE
Note: This bulletin contains revised sections. Please update your records accordingly.

UPDATE NOTE
This bulletin supersedes 01-004/03, issued 4/14/03. The step 14 of 2003 Protege & Protege5 Reprogramming Instructions has been updated.
APPLICABLE MODEL(S)/VINS
2001-2003 Protege (2.0L FS only)

2002-2003 Protege5

DESCRIPTION
Some customers may experience an engine rattle noise under light to moderate acceleration with engine coolant temperatures below 65 C (149 F) and engine RPMs between 1000 and 2900 RPM.

The noise is the result of the intentional swirl effect that is generated when the Variable Tumble Control System (VTCS) plates in the intake manifold are closed. Swirl accelerates the burn of the air/fuel mixture which reduces emissions when the engine is cold. The noise does not have a negative effect on the engine, and disappears as soon as coolant temperature reaches 65 C (149 F). There is a counter-measure to help reduce the noise in order to improve customer satisfaction.

Customers having this concern should have their vehicle repaired using one of the following procedures:

REPAIR PROCEDURE

just had this done yesterday. it's still noticeable but not as bad.

April-1st-2005 | 06:19 PM

kargoboy

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Joined: Jan 2004

Posts: 3,186

From: Pittsburgh PA

Yeah, that's pretty normal, I don't know if synthetic will help, though.
2.0s have cold-start syndrome, sounds like a friggin' Rabbit Diesel!

April-1st-2005 | 06:38 PM

mitchman

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Posts: 79

Thanks for the "official" info. So what's the repair procedure out of curiousity?

It doesn't sound like the synthetic is going to help. But in my experience with synthetic on other vehicles, it seems to take a little while to work it's way into the motor. For example; when I added sythetic (Redline MTL) to the tranny in my Miata, it took a month or so before the hard 1-2 shift went away. But the problems gone now.

Thanks again for the great info!

April-1st-2005 | 06:41 PM

Matty Mooling

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Posts: 809

From: Elizabethtown, PA

just gets reprogrammed

April-1st-2005 | 06:52 PM

mitchman

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Posts: 79

So is there an ECU flash that I should consider for my car? (2003 Protege)

Because I'm autocrossing it against the non-supercharged Mini's, I need all the help I can get!

April-4th-2005 | 12:58 AM

Rusty

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Joined: Nov 2003

Posts: 239

From: Columbia, SC

Quote:

Originally Posted by kargoboy

I don't know if synthetic will help, though.

There's no oil in the intake manifold.
The noise only lasts 5 minutes at the most while it's warming up, and then it's gone... no problem.

April-4th-2005 | 11:44 PM

cthom

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Joined: Nov 2004

Posts: 75

Had this done to my '03 LX. It involves an ECU recalibration and replacement of a valve in the intake manifold. It quieted things down greatly. Switching to synthetic has it sounding almost the same whether the temp. is 35F or 95F - which is to say, still a little noisey. Still don't know why the Pros are noisier than other cars, though.