QuestionQUESTION: Hi, I purchased a Honda Prelude from a guy who lived pretty much 1500miles away and I was able to drive it home with no problems but sometimes engine light would come on and it would go away after restarting the car. Well, when I got home next day I decided to take a look underneath and see how much rust it had and I noticed that there was oil all over the underbody of the car, and I checked oil level(it was toooo low to be driven, I wonder how it this car lasted 1518miles without breaking down) I did an oil change and noticed that oil pan seal was leaking and after replacing it the oil stopped leaking BUT when I check the oil level every 100 miles it is pretty much down to a minimum(And I do not think it burns oil, when I change oil it takes about 5.1 quarts of oil to get the level to max, by the way the engine is hybrid h22head and h23block would that have anything to do with this? and there are no oil spots underneath the car when its parked overnight) please recommend me what I could do about this?
And another thing is that my car hesitates when I accelerate, and I don't think my intake manifold is leaking air, and my rpm are sometimes around 400rpms higher than usual, why would that happen? could it be my radiator? would the flushing of it make it any better?
Thank you very much for your opinion,
ANSWER: well.. a general rule i like is buying someone else's project car is a bad idea. i don't want to make you feel bad, but there are so many possible unknowns. especially with a car you cannot see before you buy it.
the main part behind that rule is that anyone who builds a motor up has every intention of driving the hell out of it. i know i do (i have an 85 lude with a B20/vtec).
you dont mention smoking, but any oil loss with no leaking has to be burning it. on the other hand i can say that pretty much any oil leak will eventually make it look like its the pan. which it rarely is.
im assuming you mean 'minimum' by the dashes on the dip stick. the bottom dash is only a quart low. burning a quart makes far more sense. you need to really pay attention when you start it in the mornings and everyday driving for smoking. im thinking since you said vtec the car was originally vtec and only had the bottom changed. from that i assume they ran the rpms up as high as the vtec block and have worn out the ring in the H23.
i would also suggest taking it to a car wash, jacking it up and washing the bottom off as best you can.
then where you park fold out a box flat and lay it under the car when you park it for the night.
the idle is hard to say. could be related to the hybrid, the ecu they used, a gasket, vacuum hose, dirty idle motor, etc.
there are so many variables with this that would help me help you..
-car originally vtec or Si?
-any other internal work done to it?
a 94 should store the code. dig around under the passenger dash and look for a blue 2prong plug. jump that together and then turn on the key. the check light should flash a code.
there are guides you can do a search on google to find on how to get the code and how to read it.
John
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QUESTION: well, yes I guess it was a bad idea,
I was thinking of a civic with B20 in it first, but I kind of like preludes
yes I do watch it in the mornings when I start the car, smoke seems to be tiny bit more than normal(when I say normal I mean a prelude that does not burn oil)(it idles at about 1500rpms and then idle goes back to 900rpms then there is no smoke, most of it due to the cold weather, and I kind of do not believe that with that much smoke car would burn a quart of oil)
Car is h22 VTEC originally, everything is h22 except h23 block, I use h23 oil filter and h22 platinum sparkplugs)
oil pan does not leak any more I checked the seal and its dry all around which I suppose means that there is no dripping
when I got the car the guy did not recommend to exceed 6500rpms which is because of the SI h23block, but even if he did is it possible to replace the ring and how much would it cost? The hesitation while accelerating --> how much would it cost to check all the vacuum hozez and replace them?
how about the fact that it takes 5.1 quarts of oil when I do the oil change? Could it possible be a internal leak somewhere?
Overall engine runs smooth no funny noizes,
Thank you I appreciate it very much,
Answerit is possible that the rings could be worn. but i'm feeling better that he mentioned to limit the revs.
although i still find it strange he would go through the effort to put that block in, but then drive it like a grandma.
the VTEC is meant to be revved, and doesn't make the power without pushing it.
the hesitation is going to be something more complicated that a simple vacuum leak. i would bet money on it. but there are many things that could cause it. it really won't do either of us any good to list them out. you should take it to a good shop so someone can see it in person and spend some time on the car.
that is kind of ironic. i don't see enough preludes in the shop to even know how much oil they hold, but i have a 94 Si that is getting a head job and a re-ring. and a 98ish civic with an H22 that dropped a valve. so next week i will know for sure.
seriously though.. most honda's take 4.5 quarts. the H is a somewhat larger motor so 5.1 sounds about what i would expect. don't worry about that.
on the losing oil, you can have a leakdown test done.
they will hook up air to each cylinder and find out where it is losing the most. if it is the rings it should be noticeable in the valve cover. it should be done on a warm motor.
you can try looking in the valve cover and if the head looks dark with some buildup, you could be looking at valve seals.
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QUESTION: how much damage can be done to a car when driving it for a while with oil below min on the dipstick?
hopefully none. if it is really low enough, there will be enough oil to keep the light off, but the top (in the head and cams) might run dry or insufficient oil. it could wear the cam lobes or at the extreme lock up the cam in the caps.
John
