1990 Si 2.1 engine problem...Head Gasket?

[JoebenLar]

Hi all,

I do not know a ton about preludes or working on engines in general however I learn quickly. I am hoping to possibly diagnose the problem and/or find the correct mode of attack to fix the problem.

Background info:
Car has been sitting for approximately a year while I finished up school out of state. Last year on my way back home for winter break the car died when I got home and would not start again. The mechanic I took it to did a compression check and said cylinders 2 and 3 were sitting at about 60 and 70 while the other to were normal.

The engine has relatively low mileage at only 144,000 and has always burned oil ever so slightly since I bought it 3 years ago (two of which it has sat) but usually only when it was cold.

I am guessing that there was a leaking head gasket that progressed and led to the engine failure however, I am not 100% certain because I have not verified it myself. I do not have the proper tools or shop to rebuild an engine; however I would really like to save my prelude and get it running again as it has always been my favorite car.

Specific Questions:
1) Is there any way to diagnose the problem from the information provided?
2) If I need to rebuild (which is my assumption) how difficult would it be to dissasemble everything and pull the engine out? Manuals? (I would need help knowing how to handle gas lines, transmission lines, etc.)
3) I am not sure what the exact motor is (B20A5, B21...) however I do know that the manual says it is a 2.0 but it is actually a 2.1 and it is my understanding that this is a more unique motor. Would it be more feasible to simply replace the engine?
4) Finally, with all the questions in mind, I have limited resources, but I have the will that can make the way if at all possible. My restrictions are no shop to work out of limited tools (which I can figure out) and a limited amount of disposable income from which to work. I am hoping for the most thorough fix at the most reasonable cost. What are your suggestions?

Thanks to all who read and reply.

Joe

[california3rdgen]

Joe, I am in the middle of a similar issue with my 89 Si. Based on what you say I think the odds are that you have a head gasket problem, with compression leaking between cylinder 2 and 3. It could also be bad valves, or bad piston rings in both those cylinders, but I think the odds are that it is the head gasket. Assuming it is either valves or head gasket you do not need to remove/replace the entire motor but rather just pull the head off the block. Not an easy task but a doable one, even without a garage. The Haynes manual has decent instructions, but the best is the factory service (downloadable at manuals.php ). I just removed the head off my 2.0 si - it took about 3 hours and required no special tools, only a very flexible hand to remove the two middle underside intake manifold bolts. I am now having my head rebuilt (some bent valves) for $200 at a local machine shop and getting a complete head gasket kit for $80 (watch out for cheap ebay kits for $40!!). Throw in a timing belt kit and you are good to go for a lot of miles for $500 and lessons learned. The fact that yours is/may be is a 2.1 does not matter for the job itself - but perhaps for the head gasket kit - I don't know if that is the same or not. Given the relatively low miles on the car I would not naturally assume the engine needs replacing. Hope that helps.

[ludelover91]

HI mine sat since 2008, and bought it off the lot and WOW now "she" sounds like a volkswagon. Got the head done, had smoke issues i was polluting the garden state more than what polluted now. 3 hours in the HOT sun to rip it apart over the weekend. to not go to a machine shop like wanted to and have it done right before was put back together. Now the timing was hard to set also. DONT get your gasket set on ebay go to a HONDA dealer itself. One company outta texas the gaskets are very paper thin. Just basically be prepared too much too mention and what a pain in the arss to get done. Finding a good local spanish shop also they like working on these type of cars, and good luck.

[spiffyguido]

I wouldn't be surprised if your head gasket is the problem. There are several clues that might further confirm this. Your car might billow lots of white smoke out the back when it runs, and/or there might be oil getting into your coolant or coolant getting into your oil. If you find antifreeze in your oil when you do an oil change it's a pretty good indicator that a head gasket has let go. Likewise if oil ends up in your coolant.

Replacing the head gasket just involves removing the head. You don't need to take the engine out, and the dissassembly is pretty easy. The only trick here is that you have to remove the timing belt in order to get the head off. There isn't anything hard about getting the timing belt off, but you will need to know how to set the timing when everything goes back together. Shop manuals can be a great help with this.

You'll need to indentify what engine you have. THere will be a stamp on the front of the engine where the transmission bolts to the block. The engine code will be printed there. You likely either have a B21A1 or a B20A5 engine.

[JoebenLar]

Thanks for the help guys! That sounds like something I can manage. I will get to work and keep you updated on my findings (engine) and progress.

Joe

[JoebenLar]

So I have taken off the distributor, alternator, powersteering pump, exhaust manifold, thermostat and done steps 1-12 for the 1988 prelude shop manual under the cylinder head/valve train heading. I can probably figure out the rest by simply unhooking whatever is attached still but alot of the items under step 13 I do not recognize and there are no references to diagrams pointing them out in relation to the engine. The exception is the four injector connectors. Found and disconnected them.

The engine is a B21A1.

Thanks for your help.

[spiffyguido]

Those connectors under step 13 will be hard to describe. Just disconnect any that seem to be in your way of removing the head. It'll be easy to put it back together as all the connectors are generally color coded and have a certain shape that makes it abundantly hard to mix them up.

Sounds like you're making great progress.

[JoebenLar]

Got them all disconnected. Actually took off the Fuel injector with the top end because it was a lot easier.

There is a new development now too. I will be needing to take the whole engine out and get it rebuilt. I can see why the compression was really bad in pistons 2 and 3; there is some minor grooving in both. I'm really enjoying taking this all apart. I've never got to see the pistons and everything before.

So I'll probably just get the manuals the engine removal and let you know the progress.

I am thinking I am going to try and get the air conditioning converted from R12 to Freeon.

Any other suggestions for components to replace while I'll have the engine out?
Tips for removing the engine? WIll I also need to remove the manual transimission?

I wish I could do the A/C myself, oh well.

Thanks,
Joe

[spiffyguido]

The engine can come out without removing the transmission, but in many ways it might be easier to remove them together. Mating the block to the transmission during reassembly is much easier when the engine is out of the car. Plus, the tranny is really easy to remove attached to the engine.

As far as stuff to replace while the engine is out:

If you are nearly due for a timing belt change, do the timing belt and the water pump while you have everything apart. It will safe you the trouble later. If you have the cash, I generally suggest that people also change the cam oil seals when they do the timing belt.

I'd also take a look at the health of your clutch. If it's getting to the end of it's life, change it while you have the engine out of the car.

[JoebenLar]

Ok, I'll probably take them out together then.

Is it easy to manually inspect the transmission or should I take it to a shop.

I remember it grabbed really well when the car was running, but I agree it would be best to make sure the transmission is in good condition while the engine is out.

Joe

[spiffyguido]

It's easy to tell once the tranny is out of the car. Just look at the clutch disc and see if the material is nearly worn to the rivets. Also check for any broken or bent splines on the pressure plate. If there are any problems, just replace the clutch, otherwise leave it as is.

[JoebenLar]

Well, it is time for an update. I have been working kinda slow (only a couple days a week) and learning as I go. I consulted a few local honda experts and determined that it would be VERY costly to rebuild and might not save me much money as I had hoped with doing the labor myself, but after some hunting and near failure, I was able to find an engine with 109,000 miles on it and I am going to receive it August 2 and then will proceed to put it in. I am getting it thru a third party and it will come with a 1-year warranty. Although this might seem anti-climactic it is quite the opposite because I have learned much about my little prelude that I did not know and have become a smarter driver and owner in the process.

Current Progress:
I just got the axles out after a little struggle. I learned that all I needed to do was take the ball joints off and then I could pull the rotor and axle away from the transmission. I have two mounts to go remove and then the engine will be coming out.

I will keep you all updated on the progress with the installation of the "new" B21A1.

Joe

[spiffyguido]

Sounds like great progress to me. Thanks for keeping all of us in the loop.