No start after intake manifold cleaning.

obscenic · December 3rd, 2012, 15:21

I'm having a hell of a time figuring this one out so I thought I would ask around here for some troubleshooting!

After doing my timing belt (and water pump etc) I had my mkIV golf back on the road and noticed a lack of power. I VCDS'd it and found that no turbo was being delivered at all. These are the steps that I took

I took a look at the vacuum lines and found that the ASV actuator nipple had snapped off. Whilst I was waiting for a new one, I took off the ASV/EGR valve, the EGR cooler, the piping and the intake manifold and took it to get cleaned at a machine shop.

With them sparkling clean I reinstalled them all except the ASV/EGR valve. I added a belly pan and replaced the side skirts (probably irrelevant but just in case).

When the actuator arrived I installed it, reinstalled the valve, hooked up the vacuum lines and electrical connections and double checked everything.

It started for about 2 seconds, and then stopped noisily. Subsequent cranking sounds pretty bad. I pulled apart all my air lines to make sure I wasn't starving the engine of air with an accidental rag leftover - it all looks clear. I took off the intake manifold and valve to check for obstructions and all looks clear. I can't quite see into the block intake with the engine still in the car, but I don't see any signs of rags or anything.

Any thoughts? I'm at a loss.

Ski in NC · December 3rd, 2012, 15:30

Check that you did not reverse the connectors for ASV and crankcase vent heat element. They have the same shape plugs and if you reverse them, the asv will close on engine start.

obscenic · December 3rd, 2012, 15:32

I should have added; it's a 2000, ALH engine.

obscenic · December 3rd, 2012, 15:34

Quote:

Originally Posted by Ski in NC

Check that you did not reverse the connectors for ASV and crankcase vent heat element. They have the same shape plugs and if you reverse them, the asv will close on engine start.

I left the ASV one plugged in the entire time.

Crankous · December 3rd, 2012, 15:42

what was the sound when it stopped? what does it sound like when you crank it now? Also get a mirror to look into the intake ports on the block with a nice flashlight you can see well. also Im sure you double checked your timing job hasnt gone bad right?

obscenic · December 3rd, 2012, 15:49

Quote:

Originally Posted by Crankous

what was the sound when it stopped? what does it sound like when you crank it now? Also get a mirror to look into the intake ports on the block with a nice flashlight you can see well. also Im sure you double checked your timing job hasnt gone bad right?

It sounded.. bad. Like something was stopping the engine from turning. I only tried cranking it once after that for fear that something had fallen into the block intake ports whilst the intake was off. When I cranked it, it had the same bad something holding the engine back noise. I've been using a mirror and a flashlight to see in, but I need to find a smaller flashlight to get a better look.

The timing belt job was done meticulously, and checked afterwards with VCDS and the timing is bang on.

Crankous · December 3rd, 2012, 16:03

Yes but have you checked the belt since the noise. even the new components that are provided by vendors fail.... the percentage is small but it does happen. Sounds like some damage has happened to me. Did you clean your Intercooler before you put this all back together? there could have been a slug of oil that made it into a cyl and locked it up.

Seatman · December 3rd, 2012, 16:32

The asv is definitely wide open when cranking? You say you left the pipes connected but you obviously must've had them off to swap in the replacement. I would check the simple things like that first before getting to worried. A tdi cranking with the asv closed or no fuel etc can sound pretty appalling compared to one that starts good.

obscenic · December 8th, 2012, 09:10

Quote:

Originally Posted by Seatman

The asv is definitely wide open when cranking? You say you left the pipes connected but you obviously must've had them off to swap in the replacement. I would check the simple things like that first before getting to worried. A tdi cranking with the asv closed or no fuel etc can sound pretty appalling compared to one that starts good.

I tried with the asv out of the loop, same sound.

KLXD · December 8th, 2012, 10:03

Did you clean the ports in the head? If not maybe a piece of junk fell into an intake port then went under a valve and stuck it open.

Hard to believe that it wouldn't mush out since the stuff is pretty soft but I've heard of this happening.

Whatsit feel like if you turn it over by hand with a wrench on the crank pulley bolt?

obscenic · December 8th, 2012, 11:24

So, i just popped the valve cover and turned it by hand and it feels like normal compression. Once I thought I had the cams at TDC I looked in the bell housing window and the ****ing mark was BANG on the arrow. It couldn't have been any more precise. I put the injection pump pin in and it went in fine. So the timing hasn't shifted or failed (HUGE sigh of relief). I'm looking into the intake ports and can't see any crud holding one open, but it's hard to say given the viewing angle.

I did not clean the ports in the head because of the risk of dropping crud into the cylinders...

Quote:

Originally Posted by KLXD

Did you clean the ports in the head? If not maybe a piece of junk fell into an intake port then went under a valve and stuck it open.

Hard to believe that it wouldn't mush out since the stuff is pretty soft but I've heard of this happening.

Whatsit feel like if you turn it over by hand with a wrench on the crank pulley bolt?

obscenic · December 8th, 2012, 11:32

Thank you everyone so much for your input so far! It's really helped me get motivated to do this myself instead of caving and pushing it down the block to the local shop.

Ski in NC · December 8th, 2012, 11:39

Try rotating engine minimum two turns by putting a 19mm 12pt socket on crank bolt. Should feel four compression strokes and no hard spots. Compression will stop your rotation, but with effort kept on wrench, compression will bleed down and allow you to continue. CW when viewd from passenger side.

obscenic · December 8th, 2012, 11:55

On my way out to do so right now! It'll be easier now that I can see the cams.

obscenic · December 8th, 2012, 12:56

If the cams have rotated a full 360 degrees, i should have felt 4 compressions, right? I'm only feeling one and a half..