I realised my thread was down so I am resposting this for another guide.
The complete Buyers guide to purchasing an e30
Since I see posts about this all the time I thought I would take the time to consolidate all the information you need to know about buying an e30 of just about and flavor, most of the information I am passing along I have seen first hand when looking at cars, I think I looked at about 5 e30s before buying one. A lot in this article I am going to assume the person looking for a car does not know a lot about cars in general.
Here's a few things to keep in mind when picking an e30.
1. General Information
C. 325 (aka eta)
Keep in mind, I = Normal Car, IS = Sport Model, E = Economy
There are others but chances are you wont find them.
Instead of typing all the specs out of the engines, a complete list can be found here.
To make things simple, when I refer to the engine "M20" think any of of the 325 series, "m40/2" think 318i or 318is, "s14" is the m3. I am not going to cover the m3 at all, it is a completely different car, any information you would like to know about buying one can be found on www.s14.net
2. Things to look for on ANY e30:
First, look to see if there are any record of engine service, ESPECIALLY check to see if the timing belt on the m20 has been changed, and the timing chain on the m40/2 has been changed. If they have not put this first thing to do on your repair list, get it DONE. If it breaks say goodbye to your engine. Also, check to see if the water pump has been replaced. Water pump and Timing belt/chain are the first repairs you should do to any e30 without previous documentation!
Here is a list of common easily repairable problems found in e30s.
1. Window switches: They dont work well, they just suck you can buy new ones or repair.
If none of the windows work, there is a breaker button for god knows why on the dash, its right above the deck somewhere by the hazard button. It has a red outline, push it and see if that solves the windows not working problem, I have seen a lot of people tricked by this one.
2.Hole in the intake boot:
See that big black 90 degree boot thing on the right? (Note I don't have my airbox connected) If the car doesn't want to idle or stalls, chances are there's a hole in that thing. Its like $20 new and 5 min of time with a screw driver you can change it out
3. Dead Speedo, Tach, Or odometer: The odometers are prone to break in e30s, if it is you may want to question the miles on the car. They are a pretty simple fix if it is, goto www.odometergears.com
and pickup a new gear set. If all or more of these are dead it may be a bad SI board, which isnt a big deal. They are easy to replace and you can get them on ebay with new batteries cheap. The main thing to worry about is the correct mileage on the car.
4. Broken seatbelt clips. I have seen a LOT of e30s with broken seatbelt clips. They are not too hard to replace. It will require you to pull the seat out of the car but its not hard. I would suggest getting new ones from the dealer. I think they go for about $30 a pop.
5. Door Locks: Try the key in all door locks including the trunk. See if they are sticky or jammed. If they are you are generally SOL, My old 325i and my m3 both have this problem, I just expect locks on e30s not to work. Easy work around is just getting a keyless system.
There are several places on an e30 to check for rust.
A. Rear license plate light: Check around the lights for rust, This is a very common place to find it
B. Tail lights: open the trunk and pop the cover off the rear tail lights (just two plastic screw things you spin) check around there for rust!
C. Under the doors!! The window seals are prone to wear out, I didn't check this on my first car and had some horrible rust. Feel and look under the door to see if there is rust
If you made it his far without walking away good! So lets move onto the test drive.
While driving here are some thing to check, and some questions to ask yourself.
A. Let go of the steering wheel while going straight on a nice paved road, make sure the car does not veer off on its own, if it does, you probably need an alighment.
B. Do this again while braking, does it veer now?, Is there any brake grinding of squealing?
C. If the owner is not with you, hit some potholes! Check to see if the shocks are blown, do they make an awful noise when you hit potholes? Does the car "shudder" when you hit them? This may be a sign of blown shocks.
D. Try cornering hard, can you hear the wheels grind? If they do it may be a bad wheel bearing, which can most people cannot replace and will have to take to a shop.
E. Is the exhaust loud? Check for leaks or holes
F. Redline it! Does all hell break loose if you get to redlines? I did that to one e30 and it just killed it, the engine acted like crap afterwards!
G. If the car is manual, pull over, push the clutch down, put it in 3rd.. Now Drop the clutch. If the car dies instantly good! that means the clutch is probably in ok condition, if that car pulls itself forward a bit before stalling the clutch may be going out.
H. Test the cruise control!
8. General things too look for that are not e30 specific:
A. Is the paint faded or chipped?
B. Tires!! How much tread is left? Are they all the same brand and model? Is there any unusual wear marks?
C. Check all the lights, see if any are blown or whatnot
D. Check the AC
E. Let the car idle for a while, does it overheat? This may be a bad fan clutch (the mechanical fan on the front of the engine)
F. Does it overheat after driving a lot? Could be a bad water pump
G. Is the coolant black or grimy looking? This is probably a bad head gasket (lots of work for you to do, lots of money for a shop to do)
H. Pop the hood, Are there any parts with numbers written in "paint" on them? These would be parts for a salvage yard, may make you question some things. Although it may not be a bad thing, its just something to keep in mind about the overall care of the car.
9. Trivial things you may or may not care about.
A. Check the dash, if its cracked it sucks to replace. But can be done
B. Recline the seats all the way back, then pull the lever to make them come up, do they come up on their own? Or are they broken and need to be pulled up by hand?
C. Headliner ripped? Whats the overall condition of the interior? Think about how hard or what it would cost to fix problems.
Bumpers, bumpers, bumpers! By Ryan Stewart
There are a lot of different bumpers out there and there are a lot of people who hate thiers so maybe we should cover some of the basics of the E30 bumpers.
First there are the E30s made before 1988. All E30s made before 88 either got the international chrome bumper or the very large aluminum and rubber 5mph bumper that looks like this:
These cars can NOT take the plastic bumpers without heavy modification shown in Jordan's tech article. And no, there is no easy way that doesnt result in it looking horrid.
For cars made in 1988 and beyond you CAN install the plastic bumpers everyone knows and loves because those cars have the lower rear arches. On the cabrios you may want to install the latter valance to finish the update but they are a bolt on mod (except for cutting the tow hook):
For those of you who have the late model International bumpers you might wanna know, "How can I be more Euro?" Well dont fret, you too can have the opportunity. The only difference in the late model Euro bumpers is the deletion of the sidemarkers. You can get the trim that doesnt have the sidemarkers and then sell your sidemarkers to someone in Europe, they are the shizzle over there.
Now before you guys with the ugly, horrid, evil US 5mph bumpers start crying there is an out. The international market bumpers for the early cars were slick little chrome units that look great and are a bolt on mod (only drill 2 holes) for the early cars.
These are what they look like over the stock US valance and with a stock rear:
Then if you have plastic bumpers and money (they are expensive) you can install the mtec2 bumper covers and bodykit:
Just to reiterate. Unless you have lots of money or own a bodyshop you cant have plastic bumpers look right on a pre-88 car.
10. Going in for the kill!
If everything is looking pretty good to you here are some tips for buying a soon to be e30 (hopefully)
A. GET A CARFAX, I cannot stress this enough, although its not the best tool, its an easy one to use. Carfax can show if anything has happened to the car.
B. Get a blue book quote! www.kbb.com
Although this usually doesn't upload to a lot of e30s, its a nice tool to hold over the owners head to try to get them down in price.
Bargaining: Here's some lines I use to try and get prices down
"The car looks nice, but it does have a lot a miles, and you know that takes away from value"
"Yeah but, blah blah blah is wrong with it, and you know the cost of getting these things fixed will add up to be a lot even though they are not big issues"
I always low ball on my first offer, just to see how the owner will take it. Just see what their reaction is and take it from there. ALWAYS try to get them down, I mean hey, you don't have anything to lose might as well try!
I think this about covers all the basics to buying an e30, I hope this was helpful. Happy hunting!
References and tech site for help