Technical Bubbling Knocking noise

[MadMan0]

It is what it is i guess.

Driving home from shops, then a loud bubbling knocking noise from engine

Didn't try flooring it when this happened, just continued at same speed. it when away after ~ 30 seconds

Thoughts are coolent related? what do you all think?

 

[bredsticz]

Was it coming from under the bonnet or the centre console?

 

[DaveMcT]

Bubbling noise usually = coolant and most of the time means the head gasket has failed.

 

[MadMan0]

Sounded from Engine - under the bonnet.

The car seems to be moved ALOT by wind atm a large gust changed the lane i was in on motorway - mabey took out too much wieght?

The car still pulls well, coolent and oil and both going down but over past 400 miles dropped mabey 2mm on dipstick and an inch in coolent revsi

 

[DaveMcT]

Coolant level should not move at all and any bubbling noise = air in the system. Air means the head gets over-stressed warps and usually takes out the head gasket.

The dropping coolant level and (presumably) no visible leaks means its got to be going internally so 10-1 the head gasket has failed due to low coolant.

Coolant from the head gasket can drain into the sump and water/oil don't lubricate the engine very well. Coolant going down the exhaust is bad for the lambda and catalyst.

Doing nothing could be the most costly option

 

[MadMan0]

The coolent has been slowly going down since i had the car, it's not a new problem. i think there is a leak at heat matrix becuase of darker colour at one conection, not alot is being lost so it would be a VERY small leak if any.

Another thought is that the coolent is very diliute atm, waiting for time to free up so i can change it - due soon anyway. my thought is that dilute coolent will vapourise at higher temps and get out of pressure valve?

Oil is recent but little bubbles in the oil have been causing me concern here. The same little bubbles are in the mk2's oil also, engine management light is on in the mk2.

Most of dash bulbs in my mk1 have died so i dont know if the engine mamangment light is on or not.

Car's well over due (7,000 - 10,000 miles) it's Major service, including cam belt, brakes, valve clearencess etc etc...

The HG is not looking like it's leaking from outside but might look at replacing it when i get new timing & water pump fitted at this upcoming Big service

 

[DaveMcT]

At least get the compression tested and the coolant sniff tested ASAP. If ok no need to rush the service (sort of). But if trouble is found & not sorted PDQ, the consequential repair costs could go ballistic.

 

[bredsticz]

Head gaskets can take a long time to go and even when they go they don't tend to leak to the outside of the engine. Sounds like headgasket to me.

Simple test even easier - run the car with the radiator car off. Give it a few minutes and see if you see any bubbles at all in it. If so then Head has definately gone

 

[MadMan0]

Head gaskets can take a long time to go and even when they go they don't tend to leak to the outside of the engine. Sounds like headgasket to me.

Simple test even easier - run the car with the radiator car off. Give it a few minutes and see if you see any bubbles at all in it. If so then Head has definately gone

Cheers for that, ill check soon

 

[mcjacko1987]

any luck?

 

[scottishpunto]

Same thing was happening to me mate, took it to garage after about a week as I didnt have a clue what it could be and was the head gasket. I'd get it checked asap mate dont wanna run with it to long just incase. Or do as bredsticz says and run the car with the cap off and of it boils and bubbles out then its defo HG. Just wish i'd know that wee tip before I kept driving it for a week after it started making that noise.

 

[MadMan0]

Just ran it upto fan, no New bubbles appearing in coolent but the same Small bubbles that where on dipstick are in coolent - before starting engine

Also now a crackiling sound - im think HT Leads but cant see anything, too sunny here atm.

Another short motorway journey today. Currently done around 120 miles since the sound started..

 

[DaveMcT]

In the dark spray a water mist over the plug leads. Any flashes mean you need new leads.

If there are watery bubbles in the sump oil that appear on the dipstick then its almost certainly blown the head gasket big time. Get it professionally checked ASAP.

You will also need to find out why the coolant level dropped enough to blow the head gasket. There will be a leak elsewhere in the system rad heater, hose, etc. If that's not fixed the HG will blow again.

 

[MadMan0]

You will also need to find out why the coolant level dropped enough to blow the head gasket.

The coolent level has never dropped below the Min mark..

How much should i expect to pay for a Professional garage to check HG?
Cheers

 

[bredsticz]

The coolent level has never dropped below the Min mark..

How much should i expect to pay for a Professional garage to check HG?
Cheers

Sniff test is all you need. £5 max I'd say

 

[MadMan0]

Sniff test is all you need. £5 max I'd say

Sounds reasonable i guess

Thanks, anyone know a place to have this done in North Chingford?
I'll have to get it done at weekend

A Long list of new parts to get Costs looking around £600 on parts alone Is it worth it....

Clutch, shocks, brakes, timing belt, HT leads, Water pump, Suspension bushes, HG, Gear oil, Engine oil, Wiper blades + Bodywork (not urgent) + Service

 

[mcjacko1987]

Sounds reasonable i guess

Thanks, anyone know a place to have this done in North Chingford?
I'll have to get it done at weekend

A Long list of new parts to get Costs looking around £600 on parts alone Is it worth it....

Clutch, shocks, brakes, timing belt, HT leads, Water pump, Suspension bushes, HG, Gear oil, Engine oil, Wiper blades + Bodywork (not urgent) + Service

a lot of that is service parts. least you know once you have spent all that then it should be reliable for another few years

 

[MadMan0]

Car now isn't starting very well. used to take within a second to start, now takes around 8 I'll try and fit new coils and HT leads today, plugs aren't long new (around 2 months)

Anyone know how to get oil off the tyres?

slid though an oil spill coming off motorway yeserday - slid onto roadabout close call

 

[Kerim]

Crap when I start my car for the first time of the day usaly in the morning when its cool I get a bubbly noise i rev it tiny bit and it makes the noise again wait 30-60 secounds and it wont do it? So strong chance my head Gasget is gone? I changed my coolent 2 weeks ago I did let air out of it via the nipple. So do i need to tunrn the engine on and take the coolent lid off and it it bubbles I got a HG problem?

 

[scottishpunto]

Crap when I start my car for the first time of the day usaly in the morning when its cool I get a bubbly noise i rev it tiny bit and it makes the noise again wait 30-60 secounds and it wont do it? So strong chance my head Gasget is gone? I changed my coolent 2 weeks ago I did let air out of it via the nipple. So do i need to tunrn the engine on and take the coolent lid off and it it bubbles I got a HG problem?

When mines was bubbling etc; it was doing it when the engine was warm not when it was cool, not to sure about if it would be the HG if your hearing a bubbling noise when cold though. I'm sure but im sure one of the more experienced members will tell you though.

If you want to check the turn the engine over and take the radiator cap off and if it boils/bubbles out of the coolant tank then most likely HG.

Craig

P.s Did you open both bleed nipples when bleeding the system ?