NewBeetle.org Forums banner

1 - 20 of 26 Posts

·
Registered
Joined
·
26 Posts
Discussion Starter #1
Hi All,

I hope this is the right place to ask this question. I'm new to this forum, VW Beetles, and turbo cars for that matter.

ok. Bear with me here...
I replaced the broken stock air-box on my 2001 1.8t beetle. I bought it with a broken air-box and decided to save up and buy a cone filter to slap on the front of the intake.
After I installed the filter is when I noticed a ticking sound when I demand anything above 40% throttle in 3rd gear and above. The ticking never speeds up or slows down with the engine. But once I demand a certain level of throttle or above, there is this ticking sound. I can even adjust my foot/throttle to balance back and forth between when the ticking happens.
To me, it sounds like something is lose or like a valve tick. But I have only heard this once I removed the stock filter and housing and replaced it with the cone filter.

Any help or knowledge is hugely appreciated. I'm new to turbo cars and don't know if this is something really bad.

Thanks,
 

·
Registered
Joined
·
26 Posts
Discussion Starter #3
Thanks for the quick reply. I will try and see if I can catch a video...it may be hard to pick up though...
 

·
Registered
Joined
·
26 Posts
Discussion Starter #5
Maybe make a video; so we can hear the sound? A simple first start would be; put the old airbox back on and see if the sound, goes away?

billymade-- I reinstalled the stock airbox. I didn't hear any ticking. Is it possible the stock airbox is muffling it? I know the turbo, DV, and engine noises were increased by putting on the cone filter. But then again, the stock airbox had only a 1 1/2 inch intake hole whereas the cone has a 3in hole. Detonation due to higher compression? (more air for the turbo?)
 

·
Registered
Joined
·
13,445 Posts
Well, I can BARELY; hear something of a sound. I'm wondering; if it is boost related and if something in the turbo system, has a leak or is bad? How is the car running and how is the boost? Are the boost numbers in the normal range and would you consider, drivability of the car normal? Are you running; a aftermarket DV? Have you scanned the car lately and are there any codes? :confused:

From a sound standpoint; I haven't driven a car with a cone style filter but I do know, the stock airbox makes things quieter.
 

·
Registered
Joined
·
26 Posts
Discussion Starter #7
Yeah...sorry about the low video quality. That is the best one I've got.

I don't have a boost gauge set up. So I don't know the boost numbers. I would consider the drivability of the car normal. A few little tiny surges here and there sometimes (Don't know if that's normal). Plenty of get up and power at the throttle!

I installed a black aluminum DV valve like this one... VW Audi 1 8T 2 7T Recirculate Diverter Valve Turbo BOV Boost Bypass Silver | eBay
Don't know if that's considered aftermarket...?

Codes of interest are: 17748, 16804, 16486
 

·
Registered
Joined
·
13,445 Posts
Yeah, that does look like a Chinese aftermarket knockoff of a genuine Forge 006 DV. If you are having surging issues; that is not normal and needs to be investigated further, repair the cause of the problem. Common surging causes; are bad/sticking diverter valves, N249 valves, N75 valves and boost leaks. The aftermarket style DV's need serviced, lubricated and have the correct strength spring installed (based on your boost levels), to operate correctly or a cheap knockoff may not work correctly at all. If you have another good DV; you might try swapping it in, see if the problem goes away. A good place to start; is to scan the car, for any trouble codes.

diverter valve testing:

Volkswagen Workshop Manuals > New Beetle GLS L4-1.8L Turbo (AWV) (2001) > Powertrain Management > Fuel Delivery and Air Induction > Turbocharger > Exhaust Bypass Valve, Turbocharger > Component Information > Testing and Inspection > Charge Pressure B

Wastegate Bypass Regulator Valve -N75 testing:

Volkswagen Workshop Manuals > New Beetle GLS L4-1.8L Turbo (AWV) (2001) > Powertrain Management > Fuel Delivery and Air Induction > Turbocharger > Wastegate > Component Information > Testing and Inspection > With Manufacturer's Scan Tool > Page 5214

Recirculating valve for turbocharger -N249- testing:

Volkswagen Workshop Manuals > New Beetle GLS L4-1.8L Turbo (AWV) (2001) > Powertrain Management > Fuel Delivery and Air Induction > Turbocharger > Intake Air Control Valve, Turbocharger > Component Information > Testing and Inspection

I had surging and hesitation for a long time; my problem, ended up being a couple of bad valves and sticking DV. Be sure; to look for any broken, split or leaking hoses. Read more here:

http://newbeetle.org/forums/1-8-liter-turbo/50602-diverter-valves-stock-motor-apr-aftermarket-vs-stock-bosch.html
 

·
Registered
Joined
·
26 Posts
Discussion Starter #9
thanks billymade for helping.

I tested my cheap chineesy black diverter valve and saw that it wasn't working as well as not holding any vacuum at all. It was only acting as a plug. I bought a XS DV I found on ebay. This one is working and holding vacuum! Now I hear the Psssst sound its supposed to make. I hope I didn't' hurt my turbo! I guess I've been driving around with the fluttering compressor surge/stall this whole time and thought it was just what my DV sounded like. :(

Anyway, back to the issue. NOW that I have a working DV, new issues have crept up. The vacuum is pulling the valve piston up while I'm driving under normal load. Isn't the DV supposed to be shut during normal driving? When I demand hard throttle, the valve seems to hesitate and then shut like it's supposed to. This seems to happen off and on. Sometimes, the engine is bucking and surging. The ticking sound now sometimes comes and goes during these moments. I also have to feather the throttle a bit after having the engine running at a higher RPM or it will die on me (I presume this is because the DV is staying open and not allowing proper pressure to the engine?). I have the blue spring inside the DV, so I know there is plenty of spring tension.
I feel like there is vacuum being supplied to the DV when there isn't supposed to be any. I'm going to test the N249 valve tomorrow and see what I get.

As for the clicking/ticking sound, I'm getting a clue that it might be my crankcase vent valve that connects to my intake. It only happens under load (when there is boost pressure being pushed back to my intake through the PCV system), so I am thinking this may be a bad PCV valve and/or crankcase vent valve? Any thoughts?

Thanks again and sorry for the long winded listing...
 

·
Registered
Joined
·
13,445 Posts
I had a feeling that Chinese DV was going to be a problem; as for the new one, from what I have read online, it is important to match the correct spring, to your current boost. This is crucial for a surge free operating DV and good drivability characteristics.

Basically, I was in the same boat as you and as I fixed any boost leaks and replaced each bad valve, the surging problem improved and went away, after replacing all of the boost related valves. Read my thread for more info; keep in mind, how long these parts have been working, the extreme heat of the engine compartment and how worn, they are after 10+ years on the road. I found most of the valves; were in a "soft failure" mode; meaning, they were "working", passed normal testing procedures but when at normal operating temps, not working at the optimum performance levels they needed to, so the boost system can work correctly. After replacing the bad/worn parts; my boost spikes, surges, changed; everything smoothed out and the boost issues went away. For me, I had driven a boost crippled car for so long; I forgot what it was like, to drive a correctly running 1.8T. As performance degrades over time; it can be hard to notice it.


Sent from AutoGuide.com Free App
 

·
Registered
Joined
·
26 Posts
Discussion Starter #11
Thanks for the reply! I agree!

I tested the N249 valve today and found that the Ohms reading is 33.8. Higher resistance than that link you sent me suggested (27 - 30). So I'm assuming the solenoid is bad. I also bought a new PCV valve. I'm going to replace these things and report back.
 

·
Registered
Joined
·
26 Posts
Discussion Starter #12
Update:
I finally had a chance to get to my PCV valve. I found that the oil breather hose that goes from the crankcase to the rubber pcv fitting had broken. Once I had the pcv valve removed I could see that it was completely plugged. I have ordered new parts and will report back to see if this changes my issues at all.
 

·
Registered
Joined
·
13,445 Posts

·
Registered
Joined
·
2,490 Posts
oil catch can

an oil catch can would do wonders for these little 1.8T turbo cars I just haven't had the chance to put one in...always busy working on other stuff. I was gonna say that you can test the N249 valve by putting battery voltage on the coil and then see if it cycles either with a vacuum pump or just regular air. 33 ohms doesn't sound like it's bad. Usually when the coil is bad it's shorted or open.
 

·
Registered
Joined
·
13,445 Posts
As noted; conventional testing methods, may not really help and they can be in "soft" failure mode, working but not at the level it needs to. This is the problem with allot of these old parts related to the turbo boost system; they can be working but not at optimum levels. Most of my parts "passed" normal testing shown in the service manual but ended up being worn and caused me boost flutter, hesitation problems. TIme (10 + years) and heat, is a factor in degraded performance of these parts. Testing a part at hot operating temps; may also help, to see if a valve has problem operating, if the resistance values are a issue and working well.

This is a factor; I had not taken into consideration and a hair dryer or other heat source, could be a way to try to replicate a hot engine compartment. This was noted in some troubleshooting threads and the addition of heat, makes sense as a way to replicate normal operational heat levels. I'm not one to "throw" parts at a situation but as I worked through the hesitation problem; as each boost related valve was replaced with new, the problem became less and eventually went away. Replacing all the valves; was not cheap but in my case, it fixed the problem and the hesitation/flutter went away.

The testing of these types of components; beyond "on/off" and resistance readings, maybe would be done with a scope with the car running in real world conditions. I don't have one or even know how to use it but many of the better troubleshooting videos I see, the resulting waveforms can really tell you allot about the health of a component. This would seem to me; be the best way to really "see" how things are working. I was at the point; where I felt I had done all the troubleshooting I could do with the resources I had and the boost related valves, were the only thing it could be causing the boost hesitation/surging problem. It would have been nice; to have "known good" parts to swap in and test results but that wasn't an option for me.

exovcds; example of testing old and new fuel pump:

https://www.youtube.com/watch?v=h9Taap5jZI0

https://www.youtube.com/watch?v=LKh5X0xpSNg
 

·
Registered
Joined
·
26 Posts
Discussion Starter #16
ok. I've been doing a bit of work here and there trying to figure this out. I found that the idle air port connection that vents just before the turbo may have been leaking. I put a new connection and hose on there and the ticking is WAY quieter but still there. I also just deleted my SAI system and threw all that out. I also replaced the pressure regulating valve ("hockey puck") and it is still ticking. I do believe that the hockey puck valve is the culprit of the ticking...but I cant figure out whats making it do so.
I bought a hand vacuum pump. I used the gauge on that to read vacuum. It reads about 18inhg at idle.
I also can hear a weird hollow hiss/"air-blowing-through-chamber" sound at my brake boost from inside the cab. Anybody know if this is normal?
 

·
Registered
Joined
·
13,445 Posts
Hmm, now that you deleted the SAI system; how are you going to pass the emissions test? You CEL's are going to be on forever (instant emissions test fail); I would put it back on. Disabling emissions controls; is a federal offense. Deleting things; does not "fix" things. Research how the emissions control work and if there is a problem; do the necessary repairs. SAI failures: typically, bad combi valve, broken hoses, bad air pump or bad switch/valve that actuates the combi valve.

https://www.google.com/search?q=Tampering+of+Vehicle+Emission+Controls&oq=Tampering+of+Vehicle+Emission+Controls&aqs=chrome..69i57j69i60.2049j0j4&sourceid=chrome&ie=UTF-8#q=federal+offense+Tampering+of+Vehicle+Emission+Controls

As for the brake hiss sound booster sound; the booster may be bad or check the hoses and check valves related to it.
 

·
Registered
Joined
·
26 Posts
Discussion Starter #18
Hmm, now that you deleted the SAI system; how are you going to pass the emissions test? You CEL's are going to be on forever (instant fail); I would put it back on. Disabling emissions controls; is a federal offense.

https://www.google.com/search?q=Tampering+of+Vehicle+Emission+Controls&oq=Tampering+of+Vehicle+Emission+Controls&aqs=chrome..69i57j69i60.2049j0j4&sourceid=chrome&ie=UTF-8#q=federal+offense+Tampering+of+Vehicle+Emission+Controls

As for the brake hiss sound booster sound; the booster may be bad or check the hoses and check valves related to it.
Where I live I don't need to check for emissions. I bought a resistor to fool the computer into thinking the pump is still there. I am also going to eventually change my exhaust a bit. So I'll be getting an O2 spacer... and with the issues i"m having at the moment...the CEL is constantly on anyway...
 

·
Registered
Joined
·
26 Posts
Discussion Starter #19
I tested the N75 valve and got 32.7 ohms.
I also finally installed a boost/vacuum gauge. That is helping me with diagnosis.
Does anybody know how to test the camshaft, and engine speed sensor? Im getting code 17748 and need to know how to test thoes sensors. I replaced the MAF sensor which fixed a stalling engine and rich fuel issue I had (or at least at the moment), but that has really increased the amount of jerking/bucking when warming up and driving. I have replaced several hoses that had holes or tares in them. I cant find any other leaks! My vacuum is at 20inhg. Today, I replaced my sparkplugs in hopes to fix the jerking. But that didn't fix it. However, now with new sparkplugs, it is going only to 5 psi boost and does a very heavy shaking and hesitation when trying to increase boost to 10psi. It does intermittently go to 10 psi but then shoots back down to 5psi. Bad N75 valve?
 

·
Registered
Joined
·
13,445 Posts
Good info here; quite a few possible, things to test and check:

17748/P1340/004928 - Ross-Tech Wiki

N75 valve testing:

Volkswagen Workshop Manuals > New Beetle GLS L4-1.8L Turbo (AWV) (2001) > Powertrain Management > Fuel Delivery and Air Induction > Turbocharger > Wastegate > Component Information > Testing and Inspection > With Manufacturer's Scan Tool > Page 5214

In my experience with bad valves; related to the boost system, unfortunately ohm readings alone, did not help me determine if a valve was bad. After 15 years; you have to assume, most of these parts are worn out and not performing as well as they should.

Lots of threads; discussing other testing methods, aside from a ohm test:

https://www.google.com/search?q=1.8T+N75+valve+testing&oq=1.8T+N75+valve+testing&aqs=chrome..69i57.4495j0j7&sourceid=chrome&ie=UTF-8
 
1 - 20 of 26 Posts
Top