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Odd engine noise when started from cold


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12 hours ago, RdeJ said:

Out of the blue I occasionally had the same sound on cold start.

It disappeared after I had the sump of to fix some leakage issues on the gasket.

While having the sump  removed, also exchanged the thrustwashers and oilpump-filter. The filter was damaged, guess it was slapping to the inside of the sump.

Robert

image.jpeg

Thats quite normal for those pickups strainers, Ive seen a few damaged like that.

Stuart.

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Here is an idea.

(Yes, please tell me it’s a load of bowlex if you think so, because it is a bit way out…)

When the engine is cold and not been used for a while, ALL the oil will have drained into the sump.

When the pump starts up, oil is dispersed all around the engine. Being cold it does not flow so well, so it takes a while to make it back to the sump.

Could it be that the oil level in the sump goes down just below the inlet pipe, and so sucks air in as well (Although I have said the oil pressure remains constant…).

Once the oil is hot it drops back into the sump faster and so does not cause starvation.

(I suppose you could run the engine for five seconds, switch off, and check the dip stick to see the state of affairs.)

 

What did Sherlock Holmes say?

“When you have eliminated the impossible, whatever remains, however improbable, must be the truth”

 

Charlie.

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Piston slap? - no one has mentioned this up to now.

For some years now, my TR4 has produced a regular noise, related to engine speed, for about the first mile or so.  I don't bother about it because it disappears.  Neil Revington commented that, with modified engines, he builds them loose - not to worry.  So I don't.

Ian Cornish

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8 hours ago, ianc said:

Piston slap? - no one has mentioned this up to now.

For some years now, my TR4 has produced a regular noise, related to engine speed, for about the first mile or so.  I don't bother about it because it disappears.  Neil Revington commented that, with modified engines, he builds them loose - not to worry.  So I don't.

Ian Cornish

Roger mentioned piston slap earlier

I think Roger just likes to type Piston Slap. In my case this is a newly rebuilt engine with around 600 miles on it.

Still waiting for the time where the weather and my schedule align so I can get back to this and do some additional tests..

Stan

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Perhaps it's just as well that I shall be seeing the eye surgeon at Stoke Mandeville Hospital a week today!

Of course, it could be short term memory problem - SWMBO is constantly accusing me of forgetfulness.

Ian Cornish

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Stan, My 2002 Forester would serve as an exemplar for piston slap. It sounds like it's crushing rocks until it gets darn good and warm. It's been doing that for all of the 200k miles I've owned it. Yours does not sound anything like that.

And Ian, I'm 3 days out from under the eye surgeon's knife and the result is dramatic to say the least. Hope your visit goes as well.

Tom

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Thanks, Tom.  Mine is just a regular check-up as I had cataract surgery (both eyes) in 2017 - a revelation!  However, I have a condition known as centro-serous retinopathy which started in the 1990s and the effect, which is fluid under the cornea, is still present in the left eye to some extent.  Hence, the left eye sees images which are distorted and somewhat fuzzy.  Fortunately, the right eye is the lead and it works well - even better after the cataract surgery.  I have always suffered from astigmatism, so still need to wear glasses in which prisms correct the double vision effect.  If I did not wear my glasses, I would see two vehicles approaching me side by side on the road - until I close one eye!

My vision is tested every 3 years for renewal of driving licence - I think this should be compulsory for everyone over 70.

Ian Cornish

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On 5/29/2019 at 4:48 AM, Charlie D said:

Here is an idea.

(Yes, please tell me it’s a load of bowlex if you think so, because it is a bit way out…)

When the engine is cold and not been used for a while, ALL the oil will have drained into the sump.

When the pump starts up, oil is dispersed all around the engine. Being cold it does not flow so well, so it takes a while to make it back to the sump.

Could it be that the oil level in the sump goes down just below the inlet pipe, and so sucks air in as well (Although I have said the oil pressure remains constant…).

Once the oil is hot it drops back into the sump faster and so does not cause starvation.

(I suppose you could run the engine for five seconds, switch off, and check the dip stick to see the state of affairs.)

 

What did Sherlock Holmes say?

“When you have eliminated the impossible, whatever remains, however improbable, must be the truth”

 

Charlie.

I'm really intrigued by this idea.

There are clearly a lot of us who have the exact same sound on cold start-up, so it's obviously a TR engine "thing".  Would be great to nail down the cause.

I'm going to run a test on this tomorrow morning and see what the dip stick says...

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18 minutes ago, TorontoTim said:

I'm really intrigued by this idea.

There are clearly a lot of us who have the exact same sound on cold start-up, so it's obviously a TR engine "thing".  Would be great to nail down the cause.

I'm going to run a test on this tomorrow morning and see what the dip stick says...

You waste your time,engine knock from cold start = only one thing oil starvation.

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5 minutes ago, ntc said:

You waste your time,engine knock from cold start = only one thing oil starvation.

So is it worth taking  the low tension lead off the coil to turn the engine over to get oil pressure before starting ?

as a test. 

Or is it cold oil ?

H

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As mentioned previously, I have a similar noise, so I can give a couple of answers to what some have suggested.

Z320 said:

“Could the fan be slightly loose on the pulley?”

I have an electric fan, and removed the mechanical fan, so no, not in my case.

 

NTC said:
” You waste your time, engine knock from cold start = only one thing oil starvation.”

The sound (to me) is not “Engine knock”, it is a “Gulping sound without engine knock”.

But maybe there is another sound that I’m missing, and the “Gulping sound” is just a Red Herring.

 

(How a Red Herring has got into my sump is a bit of a mystery though…)

 

I shall be starting my engine again in a few days time, so will try to record the sound.

 

Charlie.

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Hi Charlie,

sorry us, Bob and me, we both are thinking of the water pump pulley.

What I recently mentioned is the washer below the nut: a standard one is too weak and bends with some miles, some 100 miles or some 1.000 miles.

Then the pulley is slightly loose and makes that noice. Ask me why I know. Since that I use a selfmade washer d 25 mm x 3 mm.

Ciao, Marco

 

Edited by Z320
my bad english writing
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As mentioned previously, I have a similar noise, so I can give a couple of answers to what some have suggested.

Z320 said:

“Could the fan be slightly loose on the pulley?”

I have an electric fan, and removed the mechanical fan, so no, not in my case.

 

The person who started this thread states "standard fan" 

Bob.

Edited by Lebro
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  • 2 weeks later...

I mentioned that I was going to record the “Gushing” sound that my engine makes (made…) on start-up.

I’ve started it about 10 times since (with a few days between each one) and the sound is no longer there, yet after the initial rebuild it was there every time.

I have not put more oil in or done anything different.

It’s a mystery !

 

Charlie.

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Sounds like an airlock has sorted itself. I like those sort of problems !

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Since my original post I had to replace the harmonic damper on the TR6, move 1 cubic yard of river rock to extend a border around the porch, replace two dead Carol Mackey shrubs with dwarf mountain laurels, cut down some trees that were interfering with the electrical and cable coming into the house from the street, rewire a ceiling fan and install two LED ceiling lights in the master bedroom. So i have yet to get back to the TR3 noise. I swear I had more discretionary time before I retired.

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I had a similar noise from my TR3B a few years ago that turned out to be a loose dynamo pully (as others have suggested earlier in this thread).  It's an easy thing to check, so worth having on the checklist.

Although from your video, Stan, it sounded more like the noise was coming from the rear of the engine.

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A rainy day here but the TR3 is in the trailer so I was able to continue the search for the noise. I had the stethoscope and a length of tubing to poke around with and I could not find the source. All of the pulleys are tight, the fan is not loose.

20190618_112514-L.jpg

 

One thing that is different from when this engine was first run is that at some point after a few hundred miles I closed off the heater valve. I dont know if an air lock could be playing a role but I opened that valve anyway and I'll test again later this week and see if anything changes. Next step will be to get the car in the air and see if I can find anything from below.

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