GenVibe - Community for Pontiac Vibe Enthusiasts

All greetings from Kiev (Ukraine)!
I have already the second Pontiac Vibe – ’07 1.8 FWD low mileage - 40625.
I can not solve the following problem - after starting the engine when the engine is cold (its temperature below 104F) if you switch the transmission to position D or R - we hear this sound: https://www.youtube.com/watch?v=moWaaoBolc8" onclick="window.open(this.href);return false;

In position P - sound is not present .
When the engine warms up 104F- the sound disappears.

Installed a new belt tensioner, belt also new.

My dealer says that this is a problem in the exhaust system. But what kind exactly?

I hope very much on your help friends!

I believe it is as simple as a loose heat shield. It is very common on these cars to have one or two heat shields come loose, to include the one protecting the catalytic converter.

We checked the heat shields catalyst - no damage, sturdy mount.

Welcome to genvibe.

I hope things work out well for Ukraine, and you. Scary times.

I would first check the ceramic gaskets, one where the exhaust manifold connects to the catalytic converter pipe, a smaller one where the converter pipe connects to the muffler pipe. ( some pictures in viewtopic.php?t=17587" onclick="window.open(this.href);return false; )

Joatmon, thank you very much for your support of our country! We will win!

On the topic: I have replaced the gasket between the exhaust manifold and the catalytic convector, but did not get a positive result.

I bought new bolts and spring mounting catalyst - can they cause a problem.

I understand one thing - the sound coming from the part that heats up quickly and only under load - it's really part or exhaust system, or .... may be the coolant pump?

Remove the belt and see if you get the sound. You can run the cold engine for a short period with no belt. If the sound goes away, then it probably is something the belt turns. If it doesn't go away, then you know it is not from anything that the belt drives.

Joatmon, we are thinking identically!
I just took off a drive belt.
Tomorrow morning will check all.
I will inform the result immediately!

I checked "on cold" all pulleys with the taken-off belt in the morning: on the pump of the power steering is axial backlash the 1-2мм, the belt trensioner has minimum backlash in the fastening hobs, all the rest – any backlash no.
I started the engine with the taken-off belt - I switched transmission in D/R - silence full.
In a telephone mode I communicated to the senior master GM-dealer - on backlash there were no suspicions, sin on a belt.
Putting aside removed AcDelco 6K725 - I take new Dayco 6PK 1885 (slightly more long and much easier install).
I start the engine and I include transfer - again "roar".
Again rattles before warming up 104F and calms down - I start rotating a wheel (in one and other party on degrees 15 ) - "roar" short-term, after heating of the engine to 122F everything calmed down finally.

Motor mounts? Assuming the noise is still there with the belt off, I'd brace the engine from the front with a 2X4 wood piece between the front radiator cross-brace and the top (head) of the engine, forcing the engine to NOT MOVE when putting the transmission into REVERSE. If noise disappears, then engine movement is causing engine/exhaust to contact some body/frame member or simply vibrate on damaged motor mount.

Chiadog, thanks for council!
I understood your idea.
Tomorrow I will make experiment.

Did you get the problem solved?

You probably have more important things to worry about. Are you OK?

Hello friends!
We have disturbing time in our country therefore I didn't inform you on results...
The problem in fastening hobs of the shock-absorber of belt trensioner - at them is backlash. We made new fastening hobs and again established belt trensioner - the problem isn't present more.
Big to you thanks for the help!