Won't Start

CraigOnSummit · Post by **CraigOnSummit** » 22 Jun 2021, 06:24

I had a rapidly developing oil leak from the front of the engine. Web searches seemed to point to vvt cam sprockets seals
to be a likely area. I replaced both the seals and o-rings on both vvt cam sprockets.
I put it back together to a point where it should run, (not all of the engine mount hardware),
It started, but immediately stopped. I didn't try to restart, I wanted to look at the engine, it leaked a lot of oil,
but this time I could see the leaking area -the exhaust cam sprocket.
Too much slop in the sprocket hub. I replaced the hub and tried to start it again.
Still wont start. Same symptom - immediately started but immediately stopped.
Now, no more oil leak, but won't start, won't even try,
now, just cranks.

I believe I only disconnected one electrical connection for this job - some sort of 3-tube vacuum control, to get at
the back of the cam shafts, I reconnected it.

If I leave the key in Run position for a few seconds before turning to Start, (the fuel pump runs), the dash warning lights
go out except for the check-engine light, which flashes 8 times and remains on, along with the low oil light.
Oil level looks good now, but there were times in the last week where it reached the bottom of the dip stick.

I'm not sure where to look next ? I don't have a scan tool to read codes.
Thanks for any help.

Post by **RickHaleParker** » 22 Jun 2021, 08:12

Get a Scan tool if you are going to work on your own car. Volvo VIDA with DiCE or some other J2534 interface is the best choice.

At least go to Autozone and get the free scan, write down the DTC codes, then have them clear the codes.
Drive the car until it starts acting up. Then get a second free scan. Post the before and after DTCs here.

CraigOnSummit · Post by **CraigOnSummit** » 22 Jun 2021, 18:54

ok, my son provided a scan tool and we read 2 codes, P0420, and P2402

Post by **RickHaleParker** » 22 Jun 2021, 21:51

Did you preload the VVT hub? That is, align it VVT to the Camshaft.

Post by **erikv11** » 23 Jun 2021, 02:10

Is there compression?

CraigOnSummit · Post by **CraigOnSummit** » 23 Jun 2021, 10:33

Seems to have good compression, before attempting to start it, I turned the crankshaft by hand 2 full revolutions, all 3 timing marks still aligned.
When installing the exhaust cam sprocket, with the new vvt hub, I rotated the sprocket fully clockwise on the vvt hub before aligning the timing mark and tightening the camshaft bolt.

Post by **erikv11** » 23 Jun 2021, 13:02

CraigOnSummit wrote: ↑23 Jun 2021, 10:33 Seems to have good compression, before attempting to start it, I turned the crankshaft by hand 2 full revolutions, all 3 timing marks still aligned.
When installing the exhaust cam sprocket, with the new vvt hub, I rotated the sprocket fully clockwise on the vvt hub before aligning the timing mark and tightening the camshaft bolt.

To be clear I am wondering if (hoping!) it has compression now that you have tried to start it, not did it have it before. If not then maybe "lawn mower syndrome (LMS)" given that it started once and quickly shut down, or worse case scenario valve damage due to starting it with the belt way out of time. Bent valves are unlikely it seems, but putting it out there for consideration. One teaspoon oil per cylinder to treat LMS.

I will pass on answering the VVT questions, I still haven't done it enough times to answer without doing searches, hopefully someone will chime in on that front.

Post by **RickHaleParker** » 23 Jun 2021, 14:41

Sometimes you need to force the AI to rethink the start after a change.
1. Unplug the camshaft sensors and try to start it. ( If it works, it still many take a lot of cranking to get the first start. )
2. Let it run for a few minutes.
3. Turn off.
4. Reconnect camshaft sensors.
5. Restart engine.

EngineeringBloke · Post by **EngineeringBloke** » 24 Jun 2021, 09:00

The two codes should not be problems that prevent starting.
P0420 is a sign that the rear O2 sensor is showing that the O2 levels from after the catalytic converter are too similar to those from the O2 sensor in front and so the cat is not working (could be the O2 sensor? But more likely needs a replacement cat)
P2402 - emissions leak detector pump bad - could be a fuse or relay, or the pump itself.

Either of those would result in the check engine light as they need to be addressed but they would not prevent start.

If I leave the key in Run position for a few seconds before turning to Start, (the fuel pump runs), the dash warning lights
go out except for the check-engine light, which flashes 8 times and remains on, along with the low oil light.
Oil level looks good now, but there were times in the last week where it reached the bottom of the dip stick.

Have you seen the low oil light on after working on the cams? I assume that you had topped up the oil before trying to start the engine after that repair.

Post by **SuperHerman** » 24 Jun 2021, 09:13

Pull your MAF connector and give it a try. It will not hurt anything and will exclude it.

The two codes you show, as has been stated, are O2 related. If they were not there before double check your wiring work. You may have left something unplugged.