2005 S60 2.5T AWD - Bucking / shimmying ~1500rpm.

MarcM · Post by **MarcM** » 14 Nov 2015, 11:12

I have been running Shell V-Power Nitro+ (figured I'd run Top Tier gas as my buddy's A6 calls for) or Irving 91 (super) since I got the car. Beginning of the week I put in ~4 gals of Irving midgrade in car (tight week). Filled up after work with Irving 89 as it seemed to work fine with it. Coming back from work on the interstate I was doing 65-70mph. When I accelerated, I'd get a bump from engine, but ran fine except for those few times. When I got to the state highway, everyone does 55-60mph. Never did the bump again.
I just started car to make my way on a 19.5 mile run. Idled a bit rough. Got about 4 miles and car started bucking and lost some power. Tranny kicked down a gear. CEL started flashing. Turned around and got it back to house.
Anyone have a scan tool in the Southwestern NH area I can borrow (attended or unattended). I have a MacTools ET50 which doesn't want to work with this car. I'm going to start with a plug change and MAF clean. Any one else have ideas?

With my bad luck with fuel pumps dying with full tanks, I'm hoping that's not it.

Note: changed fuel filter (WIX) before I did the whole coolant flush debacle a few weeks ago. Car still gets ~23 mpg avg.

MarcM · Post by **MarcM** » 14 Nov 2015, 15:07

Cleaned the MAF. Wanted to pull the sensor out of the body, but finding a security TorxPlus (5 lobe star w/hole) is near impossible at this time of day. O'Reilly was only one open (probably why they do high volume business over 2 the locals). Decided to flush the snot out of it through the screen. Yeah, was dirty. Same issue when back together.
Had plugs anyway. Changed them. Autolite Platinums were in it. Could have taken them out with a finger drive 3/8"! Idiots. Gap looks to be well past .040. Several strikes: terrible plugs (unless on an actual Ford), not torqued correctly, no silicone on boots, no anti-seize and obviously weren't gapped when put in.
Same issue still, just nowhere near as bad... a slight miss on one cylinder. The witch hunt continues.

MarcM · Post by **MarcM** » 14 Nov 2015, 16:10

I should say, I put in NGK Iridium IX plugs.
Anyone have ohm readings for what the coils should be? Wondering if I have a shorted or partially open coil.

MarcM · Post by **MarcM** » 15 Nov 2015, 08:40

Ended up being coil #3. Did the coil-by-coil cable pull. Didn't need to swap positions to verify, since I found the infamous hairline crack. Not bad for 150k. Coils 1 & 5 were replaced by aftermarket. Couldn't get a Bosch one until tomorrow and need the car today, so picked up a cheapie O'Reilly one.
What happened to IPD's HD Coils? No longer making/selling? Issues arise?

Still has the light shake until it's warmed up. I'll take care of that later. Will end up doing a head gasket and rebuild the head, lap valves, check lifter gaps, sump rebuild, etc.

I did a pin by pin measurement of new coil. Although aftermarket, it must meet spec (at least initially):
Left position is ground (black lead) on multimeter. * is the spark plug connection. Combo's not shown are N/C (no connection) for ease.
1 > * = 6.7 MΩ
1 > 3 = 1.25 KΩ
2 > 3 = 38 MΩ
3 > * = 6.7 KΩ
4 > 3 = 9.5 MΩ
4 > * = 30 MΩ

Now there is SOME information out there.

Post by **abscate** » 18 Nov 2015, 01:58

There is coil info in the P80 forum and now it's here too!!

Thanks!

Marked for VRD

Post by **oragex** » 06 Sep 2018, 15:58

On a good coil (#3071341), I only get 845 ohm between connectors 1 and 3. On other connectors some numbers show but disappear right away from the multimeter screen. Also 0 ohm between spark plug hole and any connector (it seems there should be no resistance at all here).