1HZ Engine Noise

Submitted: Friday, Aug 16, 2002 at 00:00
ThreadID: 1739 Views:7941 Replies:5 FollowUps:7
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Can anyone give advice on possible engine problem. When accelerating as changing up through the gears I am getting a harsh mettalic vibration type noise. In the beginning I thought it was an exhaust problem, loose baffle in a muffler or something similar, or a leak. I have gone over the the exhaust when the engine is being revved out and found no leaks or excessive noise. The noise actually appears to be coming from the top end of the engine. I cannot feel anything and cannot seem to pinpoint it. Like I said the noise is only noticeable when accelerating up through the gears and also around the 90 kph area. The vehicle idle's as quiet as anything, seems to have good fuel economy, doesn't use any oil, and seems to have plenty of power. I have taken a mates 96 DX cruiser for a run and there is a definite difference in the amount of noise the two engines make. My vehicle has done 110 000 klms and I was wondering if the noise could have anything to do with the valve clearances, as I have noticed that they are to be checked at 120 000 klms. My vehicle is a 97 model STD 4.2 Diesel Landcruiser wagon. Any advice would be greatly appreciated.
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Reply By: royce - Friday, Aug 16, 2002 at 00:00

Friday, Aug 16, 2002 at 00:00
Checked belts? Pulleys?
AnswerID: 5774

Follow Up By: Murray - Friday, Aug 16, 2002 at 00:00

Friday, Aug 16, 2002 at 00:00
Check mounting bolt on alternator.My 100 series had /or was loose.This caused a strange vibration.By the way how important is it to have valve clearances checked.Most say it is not necessary ??
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FollowupID: 2500

Follow Up By: Goran - Saturday, Aug 17, 2002 at 00:00

Saturday, Aug 17, 2002 at 00:00
Could be something broken in the valve set up.Valves can get pretty noisy if they are out of adjustment.They make a lot of difference in 1HZ performance.Do it, you will see what i mean.
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FollowupID: 2506

Follow Up By: Stan - Saturday, Aug 17, 2002 at 00:00

Saturday, Aug 17, 2002 at 00:00
Thanks all for your suggestions, on closer inspection it appears that the noise is coming from around the alternator and other pulleys. I will pull the belts off to try and isolate the noise. Goran, any idea how much the valve clearance job costs.
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FollowupID: 2513

Follow Up By: Goran - Saturday, Aug 17, 2002 at 00:00

Saturday, Aug 17, 2002 at 00:00
Stan,i dont know how much it would cost to get the valve clearence.I did it myself,as all of the maintenance on my cruiser...so far. It is not hard but you will need the formula(shim thickness required)and basic instructions from the manual. I will be happy to describe the procedure if you wont to tacle the job yourself.
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FollowupID: 2517

Follow Up By: Goran - Saturday, Aug 17, 2002 at 00:00

Saturday, Aug 17, 2002 at 00:00
Stan,i dont know how much it would cost to get the valve clearence.I did it myself,as all of the maintenance on my cruiser...so far. It is not hard but you will need the formula(shim thickness required)and basic instructions from the manual. I will be happy to describe the procedure if you want to tacle the job yourself.
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FollowupID: 2518

Follow Up By: Stan - Sunday, Aug 18, 2002 at 00:00

Sunday, Aug 18, 2002 at 00:00
Thanks Goran. Last night I was lucky enough to pick up a bargain by getting a genuine Toyota Engine manual and also the Chasis book through the Trading Post for an excellent price. I take it that the procedure you are talking about would be in the engine manual. I will have a lot more confidence tackling jobs now I have these books. Thanks for your help with this and other questions I have asked over the last couple of months.
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FollowupID: 2520

Reply By: Mike - Sunday, Aug 18, 2002 at 00:00

Sunday, Aug 18, 2002 at 00:00
Stan, haveing done 120000ks I presume that you have changed the timeing belt, But did you change the timeing belt tensioner? The last one I did cost about $110.00. I know of several owners that have changed the belt at 100000ks only to have the tensioner bearing fail down the track. result? Big repair bill
I don't think this is your noise but it's worth checking out.
Regards Mike.
AnswerID: 5802

Reply By: Gray - Sunday, Aug 18, 2002 at 00:00

Sunday, Aug 18, 2002 at 00:00
Hi Stan, I think Mike's suggestion is sound. I also have a 97 model, on changing the timing belt i noticed the tensioner sounded dry, upon removal it had considerable sideways float as well. On replacement the engine had sounded different.
AnswerID: 5806

Reply By: Goran - Monday, Aug 19, 2002 at 00:00

Monday, Aug 19, 2002 at 00:00
Stan,just another advice. Remove overhead cam to get to the shims,forget about fancy tools that push the valves and so on.It is simple to remove and install. You will need one puller(cam pulley) and torque whench (cam brackets).
AnswerID: 5809

Reply By: Greg- Tuesday, Aug 20, 2002 at 00:00

Tuesday, Aug 20, 2002 at 00:00
Having worked in the mining industry, with regards to timing belts on 1HZ motors it is a good idea to seal up the breather groove in timing belt cover under the rubber sealing gasket with a silicon sealing
compound to eliminate dust from entering into the timing belt area. We actually had belt failures at 20- 30000km due to the abrasiveness of the dust on the belt and pulleys. Considering that a stripped and/ or broken belt WILL cause bent valves and sometimes a broken cam, it is a cheap option wurth looking at.
AnswerID: 5862

Follow Up By: Billowaggi - Tuesday, Aug 20, 2002 at 00:00

Tuesday, Aug 20, 2002 at 00:00
Hi , just a point of interest on the last post, all 1HZ motors from '99 on have a fully sealed belt cover and a better tensioner ,a gas strut type, recommended change period has gone up to 150,000k Regards Ken.
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FollowupID: 2545

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