[CAdidas333]

Hi guys!! I'm in desperate need of some help. Usually I am pretty good at DYI repairs on this bug, but this time Im stumped.

Here's my story. I have a 2001 Beetle 2.0L non turbo 5-speed. And a few weeks ago I realized that it was getting AWEFUL MPG... About 20 if my math is right... Now I have another bug, 1999 Beetle 2.0L non-turbo 5-speed (basically the same car) that gets 35+ MPG...

The check engine light has been on but to be honest, I think it's been on since the day I bought it. But yesterday, I was driving and all of a sudden I have NO power... It didn't stall, but it had no torque or acceleration... At first I floored it and powered through it, but then it happened again and eventually with my foot to the floor and the engine RPMs just as sluggish as possible tried to come up but just couldn't.... I ended up having it towed home...

I guess I should also tell you that last week I was having an issue where when I was downshifting for a turn and the RPMs would get low the engine would stall... I found a broken vacuum hose connected to the EGR valve and replaced it and that seemed for the most part to fix that problem...

Today I attempted to drive it again, it starts and idles fine, put it in Reverse, and it's got good power and torque, put it in 1st, at first it felt okay, until I tried the slightest incline and back to square one....

So I grabbed a code scanner to see what the CEL was for and here's what I got:

**P0102: MAF or VAF Circuit Low Input
**P0134: O2 Sensor CKT No Activity (Bank 1 Sensor 1)
**P0139: O2 Sensor CKT Slow Response (Bank 1 Sensor 2)
**P1420: Secondary Air Injection Control Module Electrical Malfunction
**P1255: Engine Coolant Temperature Sensor Short to Ground
**P1296: Cooling System Malfunction 17704
**P1582: Idle Adaptation At Limit
**P0112: IAT Sensor 1 Circuit Low Input
**P0137 pd: O2 Sensor Circuit Low Volts (Bank 1 Sensor 2)
**P1580 pd: Throttle Actuator B1 Malfunction

MIL ON
MONITRS
4 Inc
Catlyst
Evap
Sec Air
02 Snsr
4 Ready
Misfire
Fuel
Comp
02 Htr


So basically what Im saying is HELP!!!


... Or rather any insight would be greatly appreciated...

Thanks in advance,
Chris





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[red99]

What you have there is a mess. When you don't keep up with the maintenance then problems compound and this is what you end up with. If you drive around with the check engine light on with something that can safely be ignored (assuming there is such a thing), then when something else that you might care about more happens you'll have no way know.

You have a lot codes associated with the throttle body. Your symptoms sound like a throttle body as well. Maybe the problem will be with the cabling or a connector. Start by inspecting those. If not, you could need a throttle body. A VW-specific scan tool will give more information about what is going on with the throttle body.

You have O2 sensor codes as well. Check for proper voltage cycling using a scan tool while the engine is running. A failed front O2 sensor can cause the poor mileage that you've experienced, and ruin the catalytic converter too.

 

[CAdidas333]

So I replaced the checked all my connections and fuses... No problems there. At the recommendation of my mechanic I also replaced the fuel filter. Then I cleaned the throttle body out really good and deleted all the codes... And still having the same issue. After running for about 5 minutes I have 6 codes now and a new symptom...

P0112-IAT Sensor 1 Circuit Low Input
P0103-Mass or Volume Air Flow Circuit High Input
P1237-Open circuit: Injector 1
P0134-02 Sensor Circuit No Activity Detected (Bank I Sensor 1)
P0301-Cylinder 1 Misfire
P1240-Open circuit: Injector 4

Now I have a very pronounced misfire. I'm guessing in Cylinder 1. I had figured out that C1 was my issue before I looked up the meaning of the codes, so the P1240 was me just narrowing that down, so that one can be ignored until I delete the codes again.

Anyway I was still concerned with the MAF sensor throwing two codes so I went ahead and got a new one. But I'm stuck with this misfire issue now. I replaced all the spark plugs about a year ago and I didn't go with the cheap ones... They shouldn't be bad already... So I pulled the plugwire and spark plug on C1 to see if I had a spark and I had a hold of the rubber wire... And had my wife crank the engine and I got shocked hard... Now I didn't touch any metal so I shouldn't have been shocked... Then it hit me that could it be I have a bad wire and its grounding the spark before it ever gets to C1...

I'm no mechanic, I think I said that before... But Im pretty good at troubleshooting and turning wrenches and this by far is my most challenging case to date... ...and it's frustrating as heck to not be able to solve this thing yet....

Any more advice anyone could give??

Thanks again,
Chris



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[jfoj]

I am going to suggest I think you may have an electrical issue with all the codes you have and the type of codes you are seeing??

You likely have a mix of problems so this is going to be very hard to sort out.

The first thing I would do is open up the power distribution box on top of the battery and look for melted and charred wiring.

Also check the charging Voltage as well as verify the engine to body ground.

The next thing I would do it search YouTube for cabin air filter replacement and I would pull the wiper arms (may need a wiper arm puller, under $15 from your local auto parts store) remove the front cowl as well as both sides of the front dash and BOTH access panels under the front dash panels and look for rodent nest, wiring damage and clean out all the leaves and other debris and change the cabin air filter.

The ECU is located under the drivers side access panel under the front dash panels.

The front dash panels are actually easy to remove once you watch the YouTube videos and figure out how to do it.

Good luck.

 

[red99]

On your new injector 1 & 4 codes, the connectors for these two injectors are commonly removed when servicing the spark plugs or cables. Check and see that the connectors have been reattached firmly to the injectors.

 

[CAdidas333]

Hey all!!! Thanks so much for the help thus far... Here's an update...

So I checked for electrical anomalies and found nothing, no rodents nests, no blown fuses... Everything looks good!!

So I followed my intuition and replaced the spark plugs and wires... And took the throttle body totally off the upper intake manifold and scrubbed it with throttle body cleaner... Put the whole thing back together... And waalaa... CEL is out!! Problem solved!!!!! *high fives and fist bumps all around*


... Or so I thought. So about 5 miles into my victory lap, I get beep beep beep and a flashing overheat symbol on the dash... Pull over, kill the motor... Check coolant levels... They are good... But I've got a major issue... Got it back home and checked it out and at first somewhere in the labyrinth of hoses I can here coolant boiling... I have never had any type of overheating issues with this car... Until now... So I foolishly unscrew the cap on the overflow bottle and of course the pressurized system sends half my red coolant out of the system... And before anyone asks, no I did not ever mix green with red. And the color in the bottle is red not brown.

So I have been trolling through these forums looking for answers, surely I can't be the first to have overheating issues on a VW Beetle... And I've found some ideas but nothing definitive.

Here are my observations, maybe someone here will have some ideas for me.

-I do have heat when I turn it on, but at start in idle it is only warm not hot. During driving the heat is almost not there... But when you some to a stop I get full heat as I would expect. Weird.

-The upper radiator hose is getting very hot so I know from the forums here that means the thermostat is opening properly.

-The fans are NOT coming on. I have not bypassed the thermal switch to see if they function yet.

- I added distiller water for now until I can get some VW coolant from the dealer... The system is definitely pressurized I can feel it in the "cook and egg on" hoses...

- I have read a thread where someone was having an issue and had a upper overflow hose was stopped up and cleaning that fixed the problem, afterwards the hose "flowed like a fountain at idle... Well mine is not flowing at all, but I couldn't get the other side off without taking the upper manifold off...again....

-No white smoke from the exhaust pipe, so I doubt it is a head gasket leak, but my mechanic said I wouldn't see it unless its cold, so I will have to check that tomorrow morning before the catalytic converter gets warmed up.

So there it is. I guess it is al prevalent to know the car is throwing no codes now. Anyone with some suggestions, please let me know... This car is uber frustrating... If its not one issue it's another. Many thank yous in advance!!



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[jfoj]

I believe there is a small hose on the end of the throttle body, about 3/8" diameter, which is a water circulation hose that leads back to the coolant expansion tank.

Make sure you did not collapse or kink a hose or many times this passage get clogged in the throttle body and the system cannot purge air out of the system.

How much trash did you find under the cowl area? Likely enough to start a garden?

 

[red99]

A couple of comments:

The lower radiator hose is a better test for the thermostat. The lower hose should be getting warm. The fans not coming on can also be an indicator of a thermostat not opening. The thermostat is probably not bad, but you aren't getting proper flow in the cooling system. The on-off behavior of the heater is an indicator of air in the cooling system.

You shouldn't drive the car far with just water in the radiator. The boiling point is too low for proper engine cooling.

 

[CAdidas333]

Let me start with a huge thank you for all the help you guys have provided
Me with thus far.

So guys here's an update. I have checked almost all hoses with no success... I'm thinking more and more this is a water pump... Damn.

So question... Do I want metal impeller or plastic? Do I need the "kit" with tensioner, thermostat, timing belt? I know I have to do the timing belt, but how about the others.

Like this : http://m.napaonline.com/parts/PartsDetail.aspx?k=WPKWPK41114AM_0326564227

Or this: http://www.blauparts.com/proddetail.asp?prod=GH21100-B

Problem is that I only have limited time to fix this and I have to order both of these... I guess I can get the water pump, timing belt, thermostat and all gaskets and o-rings from autozone once I have the motor torn down, but what do you guys think is my best option here?

Also thinking another issue might be the coolant flange... I was reading a forum about overheating here and someone had that issue... But Napa has two different types and I'm confused

First type: $12: http://m.napaonline.com/parts/PartsDetail.aspx?k=ATM06A121132C_0257286291

Second type, option 1: $9:
http://m.napaonline.com/parts/PartsDetail.aspx?k=ATM038121132C_0257286417

Second type, option 2: $158:
http://m.napaonline.com/parts/PartsDetail.aspx?k=ATM038121133A_0291097995

On the second type what the heck is the difference between with or without Glow Plug Heater?!?

Haynes repair manual makes no mention (that I can find) about either of these flanges or glow Plug
heater.

Sorry for all the questions, but the more I try and research this to feel more confident with these procedures the more questions and the less sure I know what Im doing....

Thanks in advance guys!!!!
-Chris


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[PRM502STREET]

Gates makes a good quality belt and tensioner kit that you can buy at napa they are not real super expensive. Then get your water pump, and thermostat. Accessory drive belt and tensioner are optional at this time,but if you have the money to do them you might as well do it because you're right there anyway.

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[red99]

If the timing belt has never been done on your '01 you are definitely overdue. Replacing the water pump and belt tensioner would be a given. I recommend sticking to parts from German manufacturers. The Blauparts kit would be ideal.

Apparently the problem with the early plastic water pumps was the type of plastic that was used. In the newer ones the type of plastic has been changed and is now durable enough for the job. Most people still stick to metal water pumps, though.

The Diesel engine NBs use glow plugs in the cooling system to keep the engine warm in cold weather. They are so efficient that in cold weather the engine does not generate enough waste heat to run the heater in the car. Heating elements have to be added to the cooling system.

There is good info about replacing the timing belt in this thread (.pdf in Indy Tom's post):

http://newbeetle.org/forums/1-8-liter-turbo/53973-timing-belt-water-pump.html

or here for the shop manual:

Volkswagen Workshop Manuals - Golf Mk4 - Removing

 

[CAdidas333]

Are there any of these instructions for the 2.0L with Manual Gearbox that you guys know about?

I found a video that was okay: http://m.youtube.com/#/watch?v=srf6jh-IvYw&desktop_uri=/watch?v=srf6jh-IvYw

But even my Haynes manual is way more specific for the 1.8L... And it's a totally different motor.

What do you guy think?


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[red99]

The second link is for the 2.0. Here is some info I found useful:

View attachment Timing belt.pdf

View attachment timing belt 2.pdf

I made a support beam to lift the engine from above similar to what is shown in the shop manual link. I used a pair of oak 1x4's supported by wood blocks at the fenders. I used threaded rod and lifting eyes to lift from the engine support points. It worked very well.