What are common issues with the B5 Platform

[TobiqueSlang]

I'm currently looking at buying a '99 B5 and I'm just wondering what some of the common issues are that you run into with them. The one I'm looking at is pretty clean and has an AEB 1.8T but a few issues the seller mentioned was that the door locks only work with the trunk and it has "the usual water leaks" but I'm unfamiliar with what those leaks are and how much effort it would be to figure out how to fix the door locks.

Most of my familiarity is in the B6 platform so I'm not sure entirely what I'm getting into if I buy this B5, any advice would be appreciated!

[benneyates]

the seals in the trunk and rear doors seem to leak a bit after a while

the locks run on vacuum

engine vacuum (hoses with holes) cause running issues a lot

[Cybersombosis]

Broken and/or missing lower door moldings
Broken rear springs
Broken Center arm rest cover
Control arms/clunking front end
Sagging headliner
Tear in the driver’s seat
Missing spare tire tool kit
Missing spare tire
Central locking pump running but no lock or unlock
Missing covers for air box and engine
Missing battery cover
Turbo shaft play
Boost leak test
Hook up a boost gauge to see what it is boosting to
Scan the car
2 key fobs

[QuattroBucc]

Only issues I encountered when my car was stock which is also AEB is the crankcase PCV/vacuum lines were rotting and a bad check valve in there, the hockey puck PCV is known for going bad, MAF problems are common with b5's I had some issues with it myself. Also most people deal with turbo bolt problems with the bolts backing out from the manifold which I delt with myself also when the car was stock. Other than that since it is AEB is it pretty simple, it doesn't have the secondary air pump and combi valve system that 2000+ models have which are known to be problematic-you don't gotta deal with those things. The PCV system for these cars either isn't that good or the car just has a lot of oil vapors, usually your intercooler hoses/intercooler/throttlebody will have oil caked on them and sometimes it even starts pooling up in your intercooler- so not a bad idea to clean the inside of those and clean throttlebody face if you get the car. Also with the Age of these cars fuel pumps are known to commonly go bad. One really annoying thing that I think is pretty common for b5's is the Air vent system, if i change the temperature desired it automatically changes how much flow comes out, if i change it to cold temperature suddenly the vents go on FULL BLAST for no apparent reason and i have to turn them down or if I turn the temperature up to 67 then vents go down automatically and I have to turn the vent speed back up, its Odd and I've seen others complain about it on "5 things I hate about my b5"" so I think its a common issue. Also its not a bad idea to have Vagcom/VCDS for these cars so you can read the ecu and clear codes and pull up live monitoring to see your fuel trims and Maf readings etc to see if the cars running right

[B5carl]

I have an 01' AWM and so for it has all the problems listed below.

The windshield wiper actuator assembly/motors go bad pretty quickly. Meaning they will get stuck and start to not work. Eventually burning the motor out. You can get a replacement motor and re-grease the joints on them.

The subframes, rear shock towers, and engine cross bar that holds the snub mount and intake to the throttle body can undergo extreme corrosion overtime if you live in a wintery area where alot of salt gets to them.

The 1.8t also needs to have the oil changed often or you will get alot of sludge issues since it's a hot running engine. You will notice it heats up quickly even though it has an oil cooler.

The connectors are hard to remove and will crack and break(coil pack harness for example) so you need the special tools to remove them or heat them up before you attempt to remove them or they will crack and break.

People also seem to have issues with the heater core going bad or clogging. I also have heating issues but I think it needs to be cleared out. I'm assuming the special pink coolant used is supposed to be replaced often.

Other than that the AEB seems to be a pretty solid motor. When I use to be a tech my boss had an AEB with over 300k that his girl friend at the time bought new. I don't think he even needed to do a head gasket but the turbo was gone at that point.

[reece_2212]

Exterior:
Faded clear coat on Santorin cars
Rust under the lower door trims if they're not already missing
License plate bulb holders usually break if looked at wrong
License plate holder screws get stripped/captive nuts rounded
Fender rust
Broken fogs
Windshield trims (around the sides) rust out
Auto dim mirrors stuck on dim or leaking

Interior:
Sagging headliner
Torn pleather seats
Collapsed sport seat bolsters
Water ingress from hood cable, ecu box, tail light seals, and clogged sunroof drains

Engines:
Blown turbos on 2.7t
1.8t/2.8 vacuum lines, timing belts not done at intervals, 1.8t had sludge issues back in the day
Plastic heater cores break/fail
PCV on any engine is likely failed or failing due to the oil and heat cycles
Anything plastic (connectors, hard lines, wiring sheaths) are likely brittle and break by touch
1.8t coil pack wiring often causes issues when the insulation is cracked and shorting out)

Transmissions:
Autos are decent typically, 01a have a tendancy to blow up in 3rd gear, 01e aren't bad.

Suspension:
Basically every single bushing and ball joint
Rusty rear shock towers
Rusty subframes
Blown struts and broken springs
Leaking steering racks
Frozen camber adjustment bolts

Misc:
At 20+ years old, these cars are often missing anything thats easily removable. (battery cover, rain tray, warning triangle, first aid kit, tool kit, spare tire hold down or even the spare tire, centre caps. etc.
Most people did not maintain them all that well so trans/diff fluid, P/S fluid, brake fluid, and coolant likely are all super old or even original to the cars.
Minor electrical gremlins (remote fob not working, mirrors not adjusting, door microswitches causing alarm to go off)


This list may seem crazy, but its really just a compilation of most of the issues ive ever had or have seen. These cars are not as bad as people say as long as the above (namely maintenance) was carried out properly.

[walky_talky20]

I think a better question is: What are things that are great about the B5?

- Body is quite rust resistant compared to almost anything else of the era.
- Almost no problems with the bottom end (block, pistons, rings) at stock power on any of the available engines (in North America, anyway). Even if you starve it for oil, you might kill the cylinder head, but the bottom end is almost always fine.
- Solid on-road feel with basically zero torque steer thanks to "virtual steering axis" front end and longitudinal drivetrain orientation. This is what makes MacPherson cars feel lesser in comparison.
- Obviously quattro is amazing. It hits all 4 wheels at once with basically equal torque - a huge advantage over "reactive" systems that require the front wheels to slip first.
- The AWD being "all mechanical" means it doesn't break. You can't blow a fuse and be back in Front Wheel Drive. The AWD always hits. Every time. If the car moves, the AWD is working.
- The center diff is all gears. There is no clutch pack or viscous unit that will wear out. Most other 25 year old AWD systems have a wear item that reduces their effectiveness over time. Not quattro. Traction will basically be like new...forever.
- Not overly computerized. When you turn the key, your hand closes a switch that energizes the actual starter motor. Imagine that. The headlight switch closes contacts that send power to...the headlights. It's Crazy!
- There is no immobilizer that will lock you out of operating your own car because of some RF chip nonsense.
- The roof gutters don't randomly rust out (looking at you, B6 chassis).

[JohnelP]

@walky_talky20 :-> you are a mind reader.... don't know how you do that, but you read my mind.
I had the same reaction when i saw the post. The question on "what is wrong with B5".... , and seeing the different replies.

If those "fix" lists that many shared above is all they did, and applies to a 20+ years old car, it is living proof that the B5 was exceptional. 1.8T AEB engine was in my opinion the best/most reliable engine the VAG group was able to provide considering the ratio reliability vs complexity. Everything "metal" refuses to surrender. Engine, transmission, you name it.
my car is a 97 AEB, and the Air conditioning still works. I bought it 17 years ago, and never touched the AC. engine took a lot a mis-treatments from my side, and it was forgiving. Did the cyl leak test 2 years ago and i had 2% on cyl 1 nd 4, and 4% leak on cyl 2 and 3.
It had its own sneezes, but, looking back, they don't count. Peanuts.

To get back on the thread, I hope to be noticed I used past tense.
If you decide to buy the B5 tomorrow and expect you will not have any issues, then I would recommend visiting any dealer for a new lease. Common problems for a ~25 years old car is not a fair question.
Anything can fail. you may/will be the first to add new failed items on the list that were not mentioned above.
Unless a b5 is your hobby. Everything "rubber" (o-rings, seals, hoses) lost their flexibility and will soon need replacement. Many rubber parts are now brittle hard. Plastic parts became very brittle too; they snap quite easy.
B5 is not anymore in junkyards to find cheap parts, and even if there is, it is uncommon you can get a reasonable good part out of them.
Cheap parts will not take you far away, and dealer parts, let's say will exceed cost of a new lease, assuming a dealer can still source parts for the car

[fouregon]

Walky and Johnel said it best.
I’ve had many “problems” in my two 2001’s. With AWM engines. Many, or all, of these would have never been an issue with proper preventative maintenance. All b5s no matter how well taken care of are old.
-They can tend to leak oil because only the valve cover gasket was changed once.. 12 years ago.
-They can tend to have steering clunk etc because the suspension was serviced never.
-They can leak coolant, vaccum, boost, because those parts have all far exceeded their service life.

People often give me trouble for how “unreliable” my cars are, but it’s a 20 year old part I was trying to squeeze 6 more months out of. It’s not unreliable, the part just should have been replaced twice by now!
You can’t be expected to replace everything ever all at once, but being proactive has rewards.

I can’t tell if this was “what specifically should I look out for before I give him the cash” or just more of a general question.

Honestly, negligence in previous ownership is the biggest thing to look out for. Missing trim, covers, rounded bolts or other evidence of hack-jobbery. Undercarriage damage could bite you if unnoticed. Evidence of service being done the right way and on time is good.
To me, the integrity of the chassis and car as a whole is more important than worrying about what wear items to look out for. Some cars will have rust underneath, some will have totally brittle plastic everywhere up top. But all will need a brake job and a new timing belt eventually.


Charles.
‘01 Avant 1.8t Tip

[Kahn10]

With the V6s...hitting the engine sump cover which is a step up from tin foil then losing all your oil. A tube of knead it should be kept in your glove box at all times because that might just get you home. Dont ask me why I know this...🤣