rb25 weird sound?

[iam2pro4u]

Ok so i just finished rebuilding my motor and putting it back in the car. Well after getting it running i have noticed this weird noise. It started making this noise and after bout 2 days of starting it up and letting it run the noise went away and the car sounded normal. I then had the car sitting for bout 4 days and when went back out and started it up it started making this noise again. The best way i can explain the noise is it sounds like the exhaust is under water when revving up. Its like a weird bubbling noise. Ive checked the base timing twice now to make sure i had it set correctly and i do. IVe also adjust on the cas and still no change. Ive checked spark in all cyclinders. Motor compression readings were.160,165,160,165,160,170. If anyone has any idea or has had a similiar problem please let me know what you did to fix it or any suggestions to what i should try to fix it. If need be i can get a sound clip

[Joe]

how big of a build is this? like forged stuff?

[NicT]

Any other issues with the car? Loss of power, wont idle properly, smoking?

Do you have a full exhaust hooked up or is it headers/turbo only?

Is it drinking water? Have you run the engine up without a radiator cap on?

I had a similar issue and it was my catilatic converter hat collapsed and it changed note when the honey comb section inside moved about changing the tone of my exhaust. But it didnt sound like it was under water though.

I also had an issue with a warped head on my crown, didnt change exhaust note but i heard bubbling and it was the the cylinders presurising my water system.

[iam2pro4u]

Yea forged pistons. new valves springs all new gaskets bearing. just basic stuff though. Yes i have full exhaust on with no cat. Yes it seems to have loss of power. Its idling fine and no smoking.

[Carl H]

sounds like a timing issue, rb motors have a burble to them normally but should rev up freely without any hesitation.
do you have adjustable cam gears?
is your mechanical timing 100% right?

[iam2pro4u]

sounds like a timing issue, rb motors have a burble to them normally but should rev up freely without any hesitation.
do you have adjustable cam gears?
is your mechanical timing 100% right?

no i dont have adjustable cam gears. Yes i have my base timing adjusted correctly. But ive been reading that people set it at 15 degrees where mine was set to 0 along with my cousins rb both set to 0 on the first mark.

[ItzGenX]

Ok, I do not think you are grasping the whole picture here. Carl is spot on by asking you if you checked your MECHANICAL timing aka valve timing aka timing belt timing etc. The 15 degrees you speak of is the IGNITION timing where you use a timing light and adjust while the engine is running by turning the CAS. Mechanical timing is adjusted and checked with the engine OFF at TDC. My first SR did the water gargle noise, and it turned out to be the timing was one tooth off on the exhaust cam.

[iam2pro4u]

Yea thats what im talking about i set it at tdc and all the marks lined up and the one on the crank pulley was set on the first line which would be 0 degrees. im not sure what you thought i meant? but were talking about the same thing correct?

[Carl H]

crank pulley timing sucks, at best its a ballpark guess...if i set my engine to tdc with 0* lined up against the front cover im off nearly 8*.
really the only way to check properly is to pull the crank pulley off and line up the mark on the oil pump with the gear to be 100% sure its correct, it sucks to do but trust me i've had to do it before to verify timing was correct.

[toadx8u]

mark i have told u this so many times already...

[iam2pro4u]

Yes but thats what im trying to explain lol i took the crank pulley off and realigned the crank then aligned the rest. Still same noise though.

[toadx8u]

If the car is driveable bring it to my house this weekend and ill take a look at it

[iam2pro4u]

Yea its driveable i just dont have it tagged or insured i guess i could sneak it there on back roads. what time would be good though.

[toadx8u]

Just text me sat...I should be in the garage working on my piece..

[iam2pro4u]

oh alright will do.

[iam2pro4u]

ok so i forgot to mention this before but my engines knock sensors are not hooked up. I recently rewired the harness to those 2 sensors along with the iacv. which i followed the how to on a thread. well after hooking up there is no blue plug to plug it into. It shows there is 2 blue plugs that are beside each other and thats where its supposed to pluf. Well i have the one plug and its plugged in but the other one has the blue plug that comes off the harness i made for the knock sensors but there is no plug for it to plug into. Could this effect my car to be running like this?

[iam2pro4u]

and i did diagnostic test and got code 21 ignition circuit and code 34 knock sensor

[iam2pro4u]

*bump*

[Carl H]

s1 engine?
if so your ignitor may be crapping out, enough to the point that the ecu is flagging it.
is the ignitor grounded properly, and the grounds related to the ignitor well...grounded?

[iam2pro4u]

yes s1 and i have a extra ignitor i tried running the car with that one and same problem. And yes the ignitor is grounded properly.

[iam2pro4u]

Ok so i was messing around today and figured out why my car has been making this weird noise. Its only running off of 5 cylinders. #2 is not working for some reason. I know for sure its getting spark and has compression but i have not yet tested it for fuel.

[Carl H]

have you verified that the coil is actually firing or are you guessing?
best bet is to unplug your injectors and twirl the cas by hand with the coil and plug assembly resting on the head, you should see a nice bright blue spark.

[iam2pro4u]

lol i wouldnt just guess i verified it. its getting spark and can hear the injector clicking but going to take it out and make sure its in all the way just to be safe. will update tomorrow morning.

[toadx8u]

UPDATE: he came buy and got a stock injector off me...replaced it and now its working perfect...

[iam2pro4u]

yupp yupp injector was bad. thanks again todd for the extra one