dochmees

If the engine is cold it makes slightly diesel car sound (chatter), but if it gets warmer the sound disappears and the engine sounds sweet. The engine were rebuilt (ported, honed and new pistons, rings etc) and valves are also tuned correctly. This sound problem was also the case before the engine were rebuilt. Is it normal for 1990 yearmade Honda CRX 1.6i-16V DOHC engine or should I be worried?

Ricky Rojales

Aftermarket pistons?

Al Bundy

forged pistons

Norcalstoppy

u gotta FULLY warmup your engine if you got forged pistons.

Jay Kim

nolimits

Why?

10K2HVN

My friends car sounds like its a diesel - turns out that his valve(s) are slightly bent!


[Modified by 10K2HVN, 11:32 PM 11/21/2002]

Jared

forged pistons dont fully expand and fill the bore until fully warm, thats why their cold specs seem "loose" in the bores. the noise you're hearing is piston slap, and if you don't let it warm up before running it, the piston slap is very rough on skirts and cylinder walls.

StorminMatt

What kind of pistons were used? Were they street-forged (high silicon) pistons? If so, it is possible that the rebuilder made a mistake and ran them too loose. If you are running race-forged (low silicon) pistons, this is to be expected.

dochmees

I used only Honda original parts bought directly from authorized Honda shop. So the pistons were directly from Honda and labeled as Honda Genuine Part. The engine were rebuilt by the very experienced rallyteam who has a lot of experiences especially in the field of WRX`s and EVO`s. It is very hard to imagine that they made mistake.

But if we emerge to this problem theoreticaly. One fackt is that in the past my car drinked the oil (Mobil Super S 10W-40) a little bit. After headwork and increasing compression ratio (head milling) the car drinked the oil a lot and smoked lvery badly. So I had no joice - must rebuilt my engine (cylinder horning, new pistons etc). After rebuilding the engine the car runs perfectly - compression was rised, no oil consumption (now using Mobil 1 5W-50), no bad smoke. One thing didn`t change (at least not very much). Like in the past when the wether is cold and so the engine, it makes a little bit chatter like sound. As it warms up everything is just perfect.

Lets presume that my pistons are little bit loose. If so why my car will not consume any oil? It tells me that if the engine is warm the gap between the pistons and cylinder walls are tight enought. So in that case all seems fine. The gap between the pistons and cylider walls can`t be too tight either, otherwise it will worn out the whole engine. In this case the gap between cylinder walls and pistons will increase anyway because when it`s too tight it worns faster. Isn`t that so?


[Modified by dochmees, 2:17 AM 11/23/2002]

Vinceg99

My car chatters when its cold and well higher rpm's and my valve seals are bad...


[Modified by Vinceg99, 1:21 PM 11/23/2002]

dochmees

When engine is warm my car works excellent - no matter what rpm you running.