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Honda Prelude FAQs

You've got questions, I've got answers. The following questions are ones that frequently come up when the technical details of Preludes are discussed. Through reading I've managed to find answers to many of my own questions, and I'm happy to pass this information on to you, my fellow Prelude enthusiasts.

Why does my Prelude have an erratic, bouncing idle?

Having an erratic idle is a problem that frequently shows up in 2nd Generation and 3rd Generation Preludes. Every time I've encountered this problem, the solution has been the same. You need to replace your IAC (idle air control) valve (sometimes referred to as the Fast Idle Valve). This valve is located on the side of your intake manifold closest to the engine compartment firewall. The valve is connected directly to the throttle body, as well as being connected to two coolant hoses. You can see a diagram here.

To replace the valve, simply disconnect the coolant lines and unbolt the valve assembly from the intake manifold. Warning: do NOT disconnect the IAC valve until your engine is cold, if you do, the pressure in the coolant lines will spray and badly burn you. Once you've got the old valve off, do exactly the opposite and install the new part. After installation, it would be a good idea to purge any air out of your cooling system as some air would have been able to enter while you had the coolant lines undone.

Why is my air filter soaked with oil?

When an air filter gets soaked with oil, it is often a sign that the PCV (positive crankcase ventilation) system is not working properly. Here is a diagram. First check to make sure that there are no leaks in any of your PCV hoses. Assuming these are fine, the problem is likely with the PCV valve. To test the valve, at idle, make sure there is a clicking sound from the PCV valve when the hose between the PCV valve and the intake manifold is pinched with your fingers or pliers. If the valve is faulty, go out and get a replacement. PCV valves are not that expensive, and can be changed in a matter of seconds.

Will a B18, B16 or H22 swap into my 2nd or 3rd Generation Prelude?

When people ask me this question, I'd really like to just tell them 'NO' and be done with it. This however is not entirely true, so I'll give you the whole story. The fact of the matter is that almost any engine could theoretically be put into any car. Sure, you could even put a jet turbine engine in your Prelude if you really really wanted to. It's not practical though.

In the context of this question, I think what people are really asking is whether or not it is practical to put one of these engines in a Prelude. To these questions, the answer is a definate no. No, it is not practical to put a B16, B18 or H22 in your 2nd or 3rd Generation Prelude. The reason for this is that these engines require many things that your Prelude does not have. For starters, your engine mounts were not designed to accomodate these engines, they are in the wrong positions. Your wiring harness and computer do not support these engines. Your axles and transmission will no fit onto these engines. The list goes on, but at this point, any sensible person would realize that it's not a realistic thing to do. Yes, people have done it. Yes, some of them have had favorable results out of such swaps. Yes, they likely spent a piss-load of money and time. And yes, I think some of them likely regret doing it.

If you really want to have an H22, I don't blame you. In this case, the best option for you is to just go and buy a 4th or 5th Generation Prelude. This is what my best buddy did, and I'm sure he has never looked back. The H22 is a beautiful motor, and it works very well with the cars it was designed to go in. Believe it or not, this route will be much cheaper than trying to get the H22 into your 2nd or 3rd Generation Prelude, and, your engine bay won't look like a hackjob.

If you really want to have a B16 or B18, you may as well just do what everyone else does and buy a Civic, Integra or CRX. This will allow for a much easier swap. Personally though, I'd rather keep my individuality, and be proud of the engines that made 2nd and 3rd Generation Preludes such great cars in the first place.