1.6 Petrol corroded spark plugs

[AntonovAN12]

Today I noticed that the hex flats of two of the spark plugs on my Mk2 1.6 petrol are badly corroded with flaking rust. 

Would it be best to remove and replace them before they get any worse or leave them alone?

I wouldn't want to round off the hex or worse shear a plug off in place.

I know that water leaking through the washer jets into the plug wells is a common problem.

I have been pulling the HT leads and checking for water every month or so since owning the car.

So far I have never seen any water in the plug wells.

 

 

[rd457]

I'd replace them, they're cheap components, and like you say, if they continue to get worse one day you may find you can't get them out, also whenever you do take them out you'll ideally want as little rust particles failing into the combustion chambers as possible.

[AntonovAN12]

I was planning to find a suitable flexible tube that I could somehow attach to a vacuum cleaner. That way I could remove the loose rust flakes before trying to undo the plugs.

[rd457]

Good plan, actually I'd try blowing it out instead, might be much easier. One thing you could perhaps try for this is to get an ordinary biro pen, take it apart such that you are left with the hollow tube, and blow through that, just like when firing off paper spit balls at school. (Remember to wear goggles or at least close your eyes though). Or you could get one of those cheap pressure spray bottles used for spraying weed killer.

[froggy8]

i was going to suggest getting a pc blower, i have got one of these for when i change my sparkplugs:

https://www.amazon.co.uk/Computer-Powerful-Electronic-Environmentally-Friendly/dp/B01FWSYOME

i will use the pc blower first to get as much of the rust as i can before i change the plugs in case any goes inside.

[froggy8]

i have only just noticed the price, i didnt get it for that, i got it for only £50.

this is what my well is like:

 

[mattsminiresto66]

Looking at that photo there is definetely water from somewhere.  Normal culprits are washer jets (as you mention) or check the core plugs for leaking, another common problem, cheap and easy enough to fix if they are.

[DaveT70]

Spray the area around the threads with penetrating oil, when the engine is warm, a couple of days, each day, before you plan to remove them and fit new.

[Botus]

16 hours ago, AntonovAN12 said:

Today I noticed that the hex flats of two of the spark plugs on my Mk2 1.6 petrol are badly corroded with flaking rust. 

Would it be best to remove and replace them before they get any worse or leave them alone?

I wouldn't want to round off the hex or worse shear a plug off in place.

I know that water leaking through the washer jets into the plug wells is a common problem.

I have been pulling the HT leads and checking for water every month or so since owning the car.

So far I have never seen any water in the plug wells.

 

 

rain comes from the right side windscreen washer jet and dumps 3 litres of water in the bit where the plugs sit - proves how modern materials work - as the whole thing can be underwater and the car will run and burn off the water - take a look after a massive rain shower - but it does put more stress on the coil pack and plug leads (its a shocking design - pun !!! ) and they will fail in the end

same engine on a volvo got a trim cover bit you can buy on eBay cheap - and the bolt holes are there on the ford !!!!  or take the lid off an ice cream carton and cut a hole for the oil filler cap and then one cable tie holds it in place - hers been like that for 3 years seems to work, sealing the heater washer jets didn't and is a faff

I expect the design feature was to cause the core plugs to rot out and overheat the engine...

[rd457]

16 hours ago, froggy8 said:

i have only just noticed the price, i didnt get it for that, i got it for only £50.

The weed sprayer bottles I mentioned can be picked up for about £10.

[froggy8]

6 minutes ago, rd457 said:

The weed sprayer bottles I mentioned can be picked up for about £10.

that is alot cheaper 🙂 

[AntonovAN12]

Thanks for the replies.

We have a compressed air line at work, so I can blow out as much of the loose rust flakes as possible.

I have noticed water on top of the cover a few times before, but have never seen any inside the plug wells. However there is a layer of brown dust in there that looks the same as the other photo. It has obviously filled up with water at some time in the past.

I have read about the Volvo cover install on here, but haven't yet got round to doing it.

The core plugs look rusty, but there is no sign that any coolant is leaking through them. If I decide to have the timing belt done, I might tell them to do the core plugs while the valve cover is off.

I sprayed some penetrating oil around the spark plugs earlier.

It is due for an oil change soon. The place I usually use for MOTs say that they can install plugs I supply for £24 inc VAT. For that I am tempted to tell them to do it at the same time as the oil change.

 

[froggy8]

it seems like you have the same issue i did, i panicked when i saw the orange rust and made a thread about it.

i managed to stop the water from coming onto the top of the coil pack by using sealant around the jet wash and since then i havent seen any water on top.

i am still thinking about either taking the top of the engine out( rocker cover?) t properly clean all the rust but keep thinking the worse if i might bodge something up while trying to put it back again.

if i havent made up my mind by the time i change the spark plugs then i will just blow it out as much as i can and deal with it for now.

[AntonovAN12]

If the rocker cover seal isn't leaking any oil, I would say it is best to leave it alone.

The orange rust isn't a problem if there isn't any more water getting into the plug wells.

[froggy8]

that is good to know, cheers 🙂 

i will just give it a blast of air and replace the spark plugs as normal.

[AntonovAN12]

I bought some plugs after work today. The parts supplier said that NGK TR5A-10 were the correct ones.

However another supplier's site claims that these are not correct, and TR5B-13s are the ones I need.

The dimension data for both of these plugs appears to be the same.

Are they interchangeable?

 

[mjt]

14 hours ago, AntonovAN12 said:

It has obviously filled up with water at some time in the past

Not necessarily. It could be just years of condensation in cold weather.

[Jimpster]

On 3/29/2023 at 8:23 AM, mattsminiresto66 said:

Looking at that photo there is definetely water from somewhere.  Normal culprits are washer jets (as you mention) or check the core plugs for leaking, another common problem, cheap and easy enough to fix if they are.

core plugs are not easy if the corrosion is bad, getting new ones to reseal can be a nightmare. Make sure the local Ford stockist has a good supply of them in. From nmemory its 8 bolts to remove the top cover for easier access.

[Jimpster]

12 hours ago, froggy8 said:

it seems like you have the same issue i did, i panicked when i saw the orange rust and made a thread about it.

i managed to stop the water from coming onto the top of the coil pack by using sealant around the jet wash and since then i havent seen any water on top.

i am still thinking about either taking the top of the engine out( rocker cover?) t properly clean all the rust but keep thinking the worse if i might bodge something up while trying to put it back again.

if i havent made up my mind by the time i change the spark plugs then i will just blow it out as much as i can and deal with it for now.

if it aint broken leave well alone

[AntonovAN12]

I had the plugs fitted along with the oil change.  Luckily the old ones all came out easily.

[froggy8]

Just now, AntonovAN12 said:

I had the plugs fitted along with the oil change.  Luckily the old ones all came out easily.

that is good news!

when i changed mine, 2 was really hard to turn. i was panicking incase it would snap off but luckily it started to ease up.