Originally Posted by Byork7
Muchos thanks sir. Got both sides working now. Just did my tune up over the weekend. Noticded a small but significant improvement in power and driveabilty. The old spark plugs were not copper, so i think my change attributed to that change in performance. Also ordered some lift support arms for my hood, as mine are shot. I noticed a small oil leak, but its looking like it just needs a new valve cover, so im picking that up today and fixing that issue. Next will probably be me getting some fuel injector cleaner for it. My mechanic neighbor told me about some really good stuff that dealers use and only dealers sell (not at autozone, o'riellys, advanced, ect.) I think he called it BG42 or something like that. Then, just little things over time to ehnace the drivebaility and power.
In the tune up category of things :
1. Check that all engine belts are properly tensioned. They should be tight to the touch. Loose belts rob your engine of power. Use belt spray on the belts and see the difference in its performance...that's what tight belts will do for you.
2. Replace air filter. If the current one looks ok, dust it off. You can also soak it in laundry detergent for an hour and rinse off with running water. Drip dry and reinstall even if damp. It will dry out in normal driving. No danger to the engine.
3. Clean out your throttle body. Remove main air hose and spray carb cleaner into the butterfly valve area to eliminate any crud. Inspect the air hose for any cracks before your reinstall it. If there are cracks, purchase a new one, its fairly cheap.
4.1 Do a diesel flush on your engine. Add 1 quart to your crankcase with the old oil, run the engine at idle for 15 minutes, then drain and replace oil and oil filter. Do this each time you service your car.
4.2 Use the correct oil rating for your engine, or use something slightly thicker at first and then see how it feels when you switch back to the correct rating down the line. If the thicker oil feels better, stick with that. If they both feel the same, switch back to the recommended rating.
5. Do a diesel fuel system flush. Add between 1-3 quarts of diesel to a nearly empty fuel tank, and then immediately fill up to full with regular. This causes the fuels to mix. Then drive normally. The diesel in the tank will clean out your fuel injectors better than any injector cleaner....and for the same price, you'll get a much higher volume of cleaner. If this is the first time you're doing this for your car, add diesel for 2-3 consecutive fillups. Thereafter, do this once each time you service your car.
6. Go for a WOT (wide open throttle) run on your car. Get those rpms to the 5k zone and hold it there for 15 minutes. If you cannot do this at safe speeds where you live, switch your transmission down to 4th or 3rd gear to get the rpms up.
7. Seafoam's effects are psychological. Any real benefit to the car comes from the fluid mixing with the engine oil and thinning it out. You can get the same effect by adding 500ml of dex3/4 transmission fluid to your engine. Its perfectly safe and will thin down the oil, giving you a short term boost. Marvel mystery oil works the same way too. I've tried all of that to no genuine effect.
8. Instead of adding sea foam to the engine, add a mixture of 50% ethanol and 50% water to the intake manifold via a tube fed into the brake booster's usual fitting. Anything from 1-3 quarts will be fine. Start the engine and hold the rpms at 1500. Hold the open end of the tube right at the surface of the mixture, without dipping into it entirely...the mixture will be sucked in via the engine's vacuum through the hose, and it will do some cleaning of your intake manifolds from the inside. Hold it at that position until you get the hang of it. Don't worry, you won't hydrolock your engine. Some water will enter your engine though and you might find the oil under the crankcase cap and dipstick a little milky...do not worry, anything from 15-60 minutes of total driving time depending on how much mixture you used, will vapourise and expel the water naturally through the crankcase ventilation system. There will always be water in the air and in oil so your engine will not be damaged. You don't need to do this immediately either, just go for a drive within 24 hours. You can drive normally i.e. hard. No issues.
9. You have the M20 engine, right? There was a post I spotted on bimmerfest a long...long time ago, which showed that seriously thick crud accumulates around the two bends of the intake manifold...the first bend midway and the second bend where it connects to the cylinder head. It was a nightmarish picture, and the poster concerned didn't realise anything was wrong at first...he had dismantled it in the process of getting to the head gasket, then saw the abomination and alerted us....I would very strongly advise you to pick up some new intake manifold gaskets, dismantle it and clean it out thoroughly using a flexible probe and lots of flushing. It will surely improve the airflow into your engine and thus your performance and mileage.
When you reinstall the manifold, make sure you use a torque wrench and have the bolts torqued down according to the Bentley manual's recommendations, and in the correct sequence. (This is highly important for the valve cover gasket (vcg) too ).
10. Check on your valve clearances when you do the valve cover gasket. Gap them and tune them up properly. They would have run out for sure. This makes a very noticeable difference to the performance and smoothness of the engine. The Bentley manual has details.
11. Unless you have evidence that the ignition coil assembly/ ignition distributor/ distributor cap / thingamajig and the spark plug wires were recently changed, purchase a whole new one. OEM. Would usually improve performance slightly, and eliminate problems due to degraded wiring. Around $200. I would only get to this after everything else has been cleared.
12. Use 4-claw spark plugs for better performance and longevity. Do not change them for the next 100k miles. Seriously. Bosch plat+4 will do the trick. However, take them out at least once a year and just inspect them.....spark plug burn marks can sometimes alert you to other forms of engine issues (please google). I believe you purchased the denso plugs, if they were the iridium versions you're good for the next 100k miles there too. An esteemed member of these forums once ran stock spark plugs on his e36 m50 (same engine as on the later versions of the e34) for almost 180k miles, with no real issues. As long as the engine's condition is normal, your spark plugs may only require light cleaning on ocassion. The iridium ones don't even require that.
13. Make sure your tyres are properly inflated. Ebay sells a neat solar powered hand held digital tyre pressure gauge. Something like under $10 shipped. Hang on to that. Make it an unconscious habit to scan your tyres' standing road bulge from time to time to sense problems early, then use the gauge to confirm. In any case, check the pressure every 2 months.
14. Autozone will scan your car's computer for free (or is that only for obd2 cars?). If the stomp test does not work, don't bother, just head right over there and get that checked. After you've had the codes read and noted, clear them on your car. The code reader can do this, or you can unplug your ecu for 5 minutes. Don't be too worried if you find many codes, some of them are very old ones. After they are deleted, recheck your codes about 1 week later. If the earlier codes have reappeared, then you do have a problem and need to decide what (if at all) you're going to do about it.
15. Use a vacuum pressure gauge to see if you have an vacuum losses on your engine, and if so, do your best to trace it. Youtube has many videos on how to use this gauge. It is cheap...under $30 shipped.
16. ** COMMENTS INVITED TO CONFIRM OR DENY ** : After everything has been done, please retune your engine by playing with your air flow meter (google for detailed writeups with pictures). There is a little allen-key bolt over on that afm that you can turn clockwise and anti clockwise to fine tune your idling and get the perfect note. You should do this after everything on this list has been done for two reasons : (a) by then you would have totally gotten to know your engine and how it sounds under various conditions intuitively, which is important for this "tuning fork" type tuning, and (b) anything else that might affect the engine has been replaced, cleaned out or upgraded. This should be the very last step. And it is reversible. The target, is to make it sound as sweet as possible when at idle. What does that mean? You'll know it when you hear it. You can only determine this after you've had your car and worked on it for a couple of weeks, so only do this at the very end.
Last edited by robertobaggio20; 09-26-2012 at 01:05 AM.