1999 V70T5M56 Poor cold idle troubleshooting Topic is solved

[abscate]

Well., got lucky this morning, No Not that.

I warmed it up for a hot compression test, and had a lumpy idle, but could hear vacuum whoosing near cylinder 4-5

All of a a sudden something clicked, a solenoid sound, whooshing stopped. and idle got silky smooth. So Ive got to find out what is leaking and where.

Ill run the hot compression numbers since Im at the 200k mark - cold/hot will be good to document too.

[abscate]

Definitely reproduced the hiss- click- silence-smooth-idle

Hiss is down around cylinder 4-5 , near the PCV-purge-booster hose assembly. Other than purge valve there arent too many other solenoids on ME7

?????

[abscate]

Wcm and I tried it yesterday at about 40F.

Cold start, silky smooth idle. I’m thinking it’s the check valve in the brake booster vacuum line, maybe? Still wondering about the “whoosh....click....good idle”though

[abscate]

Cold start today, 36F, silky smooth. It’s idlingbetter now when warm, too, almost silent

I ran cold and warm compression tests, inspected plugs, did a course of MMO, and found I had three light torque on the 4 5 cylinder intake manifold bolts. I think that was the culprit.

I also put a better clamp on my PCV top hose on the cam cover. That may have been loose, too. It’s tight now. I retorqued all the cam cover M6 and got about a third of them took a 1/4 turn or so to torque.

Feeling the itch to tick the green check box. What’s stopping me is I’m not a fan of the intake leak that fixesitself when warm, it’s like pluggedfuel filters, bad gas, or a faulty ECM

[erikv11]

This thread is riveting, it's like watching the cogs turn inside a ... ummm ...

[abscate]

This thread is riveting, it's like watching the cogs turn inside a ... ummm ...

The pun bug obviously vectors over the internet....

[abscate]

Okay, I’m going to take the plunge and also find the Volvo horns for

Post by erikv11 » 25 Feb 2018, 20:26

Cheap and easy to add to the list of items to evaluate (and worth adding):

Get some starting fluid on the edges of the intake manifold where it meets the head, especially near 4 and 5.

Awarded to Erikv this 28 Day of the year 2018 of the Swede

[abscate]

...and my intuition was correct.

I did a VAT inspection of the hoses, found nothing, so I removed the ones I could not see buried under the intake manifold and...obvious check valve fault.....

[erikv11]

I hereby return the horns, print that out and wear it all day!

[abscate]

You get to retain them until I figure out how the click and woosh magically fixed the hose....