Strange Noise From Engine area
Submitted: Sunday, Sep 04, 2011 at 21:11
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Member - Wayne B (NSW)
HI all.
Coming
home from
Tamworth the other day there was quite a loud chattering type noise which appeared to be coming from around the engine area on my HJ80 1HDT.
The symptoms were throttling off from high boost. The noise occured only occasionally but was quite loud. As soon as throttle was reapplied the noise stopped. In all it has done it three or four times on random occasions.
My thinking it is the wast
gate chattering ( vibrating ) maybe some carbon caught in the waste
gate. Anyway I was wondering if anyone else has come across this problem.
Any comments appreciated.
Thank you
Wayne B
Reply By: mike39 - Monday, Sep 05, 2011 at 17:13
Monday, Sep 05, 2011 at 17:13
I dont wish to sound alarmist but that is very symptomatic of bigend bearing wear.
How is the oil pressure under these conditions.
With mine the oil pressure on the guage noticably rises when I lift off going down a steep
hill (like Moombi)
Without any boost (throttle off) I dont see how the waste
gate could chatter?
mike
AnswerID:
464276
Follow Up By: Member - Wayne B (NSW) - Monday, Sep 05, 2011 at 20:32
Monday, Sep 05, 2011 at 20:32
Mike
New Bearings fitted 10,000km ago. Not a bearing sound, I am sure it is not that
Cheers
Wayne
FollowupID:
738194
Reply By: Roughasguts - Monday, Sep 05, 2011 at 17:54
Monday, Sep 05, 2011 at 17:54
Internal waste
gate or internal waste
gate?
If it's an external waste
gate then it may even sound like a jacobsen brake if it jams open momentarily.
Cheers.
AnswerID:
464283
Follow Up By: Member - Wayne B (NSW) - Monday, Sep 05, 2011 at 20:36
Monday, Sep 05, 2011 at 20:36
Roughas.
Jacobson brake ! yes that is exactly what it sounds like.
Yep I think it is the wast
gate. Guess we will have to wait and see if anything develops
Cheers
Wayne
FollowupID:
738195
Follow Up By: Member - Wayne B (NSW) - Monday, Sep 05, 2011 at 20:51
Monday, Sep 05, 2011 at 20:51
Dont think it is an external
Gate I think its just a flapper valve that dumps back into the exhaust. I feel this could still cause the noise
Cheers
Wayne
FollowupID:
738197
Follow Up By: Roughasguts - Monday, Sep 05, 2011 at 20:57
Monday, Sep 05, 2011 at 20:57
Well it kinda makes sence to me if your flat out making heaps of boost then back off the throttle completley! then the turbo is still spooled up at Max boost for a second. But having the throttle closed the motor isn't going to suck all that boost up so it throws the boost out the waste
gate, making a sound like a J brake for a moment.
Cheers.
FollowupID:
738200
Reply By: Member - reggy 2 (VIC) - Monday, Sep 05, 2011 at 20:40
Monday, Sep 05, 2011 at 20:40
Hi Wayne
I have been chasing this type of noise for yonks and have not been able to find it
I presume that yours is turbo type motor
Have spoken to a lot of mechanic's but because it only does it intermittently you can't sit anyone on the engine bay to find it
mine seems to do it more when it is cool,when you change down to go through a roundabout.
Sorry this does not answer your question though.
My truck is 2004 turbo 79 series, it does not seem to affect the performance,I have been out to Desert a couple of times it seemed to disappear while there
Cheers Reggy2
AnswerID:
464296
Follow Up By: Member - Wayne B (NSW) - Monday, Sep 05, 2011 at 20:57
Monday, Sep 05, 2011 at 20:57
Reggy.
Intermittent problems are always a pain to find and fix.. This noise only started the other week. We did a trip across the Simpson recently no problems then.
Thinking about temperature ??? If I recall no the occasions it occurred the engine would have reached normal operating temperature maybe traveling for 10 minutes from cold start up but the engine was certainly not hot. There is no change in performance and as soon as you accelerate even slightly, the noise goes
Cheers
Wayne
FollowupID:
738201