Valve stem seals replacement?

[ropecharrmer]

My Mk7's a bit of a basket case right now. Been making a ticking sound for a while and not starting when hot, and now just started blowing big clouds of blue smoke on startup and after sitting at the lights so think it needs some attention.

The blue smoke seems like a valve stem seals problem. Can I replace these without taking the cylinder head off? Is there a good way of stopping the valve dropping into the cylinder?

Thanks for any help.

[knobby1]

My Mk7's a bit of a basket case right now. Been making a ticking sound for a while and not starting when hot, and now just started blowing big clouds of blue smoke on startup and after sitting at the lights so think it needs some attention.

The blue smoke seems like a valve stem seals problem. Can I replace these without taking the cylinder head off? Is there a good way of stopping the valve dropping into the cylinder?

Thanks for any help.

Highly unlikely to be valve stem seals, they rarely give trouble. How long has it been blowing smoke..?? Check to see if there's a silly amount of oil in the intercooler and boost pipes/hoses.

When was a major service last done..?? Is it a Euro-4..?? If so, when were the pump pilot and injector learns last done..?? Fuel filter replaced..?? Injector clamps loose..?? Injector/rocker cover seals leaking..??

Have you had the codes read..??

Lord Knobrot

[andz327]

More likely to be turbo smoking than valve stem seals

Sent from my SM-G975F using Tapatalk

[ropecharrmer]

That's good to know, thanks for the tips. Valve stem seals didn't look too easy.

Smoke is fairly new and figured I couldn't drive around like that for very long. Was giving the cars behind a bit of a shock when I pulled off

Doesn't seem to be too much oil in the intercooler intake, and the turbo was replaced maybe 15,000 miles ago. There is oil around the rocker cover though so I'm going to replace that gasket and the injector o-ring seals and see how that flies. Ford wanted £100 for a set of the injector washers though! So think I'll see if I can get away with re-using those.

Had new filters and oil recently and no check engine light showing. I have forscan so will give the pump and pilot learns a go if it stops spewing oily smoke

[knobby1]

That's good to know, thanks for the tips. Valve stem seals didn't look too easy.

Smoke is fairly new and figured I couldn't drive around like that for very long. Was giving the cars behind a bit of a shock when I pulled off

Doesn't seem to be too much oil in the intercooler intake, and the turbo was replaced maybe 15,000 miles ago. There is oil around the rocker cover though so I'm going to replace that gasket and the injector o-ring seals and see how that flies. Ford wanted £100 for a set of the injector washers though! So think I'll see if I can get away with re-using those.

Had new filters and oil recently and no check engine light showing. I have forscan so will give the pump and pilot learns a go if it stops spewing oily smoke

If you do the rocker cover gasket and injector rubber seals, the copper injector sealing washers and clamp bolts will also need replacing. The injector bores will need reaming and cleaning also or you'll be doing it all again soon.

Lord Knobrot

[ropecharrmer]

Noted, thank you. All parts in the post

[therightangle]

Highly unlikely to be valve stem seals, they rarely give trouble. How long has it been blowing smoke..?? Check to see if there's a silly amount of oil in the intercooler and boost pipes/hoses.

When was a major service last done..?? Is it a Euro-4..?? If so, when were the pump pilot and injector learns last done..?? Fuel filter replaced..?? Injector clamps loose..?? Injector/rocker cover seals leaking..??

Have you had the codes read..??

Lord Knobrot

Apologies for tagging onto an old thread, but my Tranny's symptoms are similar and I know knobby and Andz seem to know their stuff from other threads on here.

Mine is a Euro4 3t 2007 camper with 65k miles.
Blue smoke on cold start and after idling but not as bad as what was described above by ropecharmer. Doing it probably since I got it 20k miles ago.
Oil air and fuel genuine filters and good oil in the last 5k.
Pump and pilot learns and new MAP also in that time.

No current codes but 2 intermittent ones for EGR, which it has had 2 new EGRs about 10k and 15k ago when I bought it.
Intercooler floor is wet but not sloshing around with oil and turbo intake and short breather pipe are fairly dry.
MAF desired is about 3 times MAF actual so assuming I need to do EGR next.

MAP still getting dirty and some oil signs around 3 injector rocker seals but no bubbling. Idling well and reasonable power though maybe should be more for a 130hp, I don't know.
Breathing at filler cap with slight spray but quietly/evenly, not chuffing.

Assumed it was injector seals based on a lot of the advice here but tbh there is no fuel smells and wondering now about valve seals.

The Denso injectors are out and don't look bad with carbon but did have oil and dirt/grit down to tip which I assumed it picked up on the way out, and the copper washers look like they've never been squeezed. The injector clamps weren't loose though. They still had the black plastic covers and may never have been touched since the factory.

At this stage I'm wondering how likely valve seals are? I'm in at the deep end so far with injectors so tackling valves would be a serious task for me.

Appreciate any thoughts from anyone here

[DanMK7uk]

Make a post mate and you should get some help as often things get overlooked when tagged into an existing post.

[metalworker0]

Apologies for tagging onto an old thread,

No current codes but 2 intermittent ones for EGR, which it has had 2 new EGRs about 10k and 15k ago when I bought it.
Intercooler floor is wet but not sloshing around with oil and turbo intake and short breather pipe are fairly dry.
MAF desired is about 3 times MAF actual so assuming I need to do EGR next.



Appreciate any thoughts from anyone here

if you had two new EGRs so soon after each other .. then maybe its your driving style .. short runs , stop starting driving or not giving it the beans excessive idling, not getting to temperature ... and the egr is at fault again ---- some garages will not clean them as labour at £100 an hour means they just replace,

People get on at me about AI .. but sometimes i agree with it and it saves me a hell of a lot of typing and explaining .. if you have an ice cream van etc .. then that is the cause

so here's the AI on it

AI Overview
Exhaust Gas Recirculation (EGR) systems operate in a harsh environment, and certain conditions can lead to accelerated clogging, sticking, and premature failure. The worst conditions for an EGR system typically involve, but are not limited to, short-trip city driving, frequent, prolonged idling, and high-mileage operations with poor maintenance.

Here are the specific, worst conditions for an EGR valve:
1. Short Trips and Cold Operating Temperatures
EGR systems require high exhaust temperatures to burn off accumulated soot and carbon.

The Cause: Frequent, short trips that do not allow the engine or the exhaust gas to reach full operating temperature.
The Result: The soot does not burn off and quickly accumulates, leading to a "sticky mess" in the valve and intake.
Why it's worse: Cold, stop-start, or urban driving results in higher soot production compared to long, high-speed motorway driving.

2. Prolonged Idling
The Cause: Leaving a vehicle idling for long periods (e.g., in traffic, warm-ups, or service vehicles).
The Result: Idling creates low exhaust gas temperatures and low pressure, encouraging soot to settle and build up in the valve and cooler.

3. Poor Maintenance (Old Oil and Dirty Air Filters)
The Cause: Neglecting regular oil changes or failing to replace air filters on time.
The Result: Degraded oil and restricted airflow increase the amount of oil vapor and unburned fuel passing through the exhaust system. This mixture forms a thick, sludge-like deposit that clogs the valve rapidly.


4. Low-Quality Fuel
The Cause: Using fuel with high impurities or lacking proper detergent additives.
The Result: Poor-quality fuel burns less efficiently, producing more soot and carbon particles that directly coat the EGR valve, causing it to stick or clog.

5. High-Load/Low-Speed Driving
The Cause: Driving on steep hills or hauling heavy loads at low engine speeds (lugging the engine).
The Result: This causes high combustion temperatures (which are hard on the valve) combined with poor airflow, leading to faster soot buildup and increased potential for the valve to seize, especially in diesels.
6. Extreme Weather Conditions
The Cause: Very cold winters and humid summers.
The Result: These environments speed up corrosion of the metallic components of the EGR valve and increase the rate of carbon buildup.

Summary of Consequences
When exposed to these conditions, the EGR valve typically fails in two ways, both of which cause poor engine performance:
Stuck Open: Causes rough idle, stalling, heavy smoking (black), and severe loss of power.
Stuck Closed: Leads to excessive, uncontrolled combustion temperatures, resulting in engine knocking/pinging and potential engine failure.

all the best.mark

[DanMK7uk]

Might be worth checking for play on the turbo shaft OP.


Check for any excessive radial (side to side) play, & should be no detectable axial,(in and out) play.

EGR valves, work of the devil just like DPF.

Horrid bloody ideas !