OV9

What a ballache

tim wrote: Mon Jul 14, 2025 9:57 pmWhat a ballache

This is week 7. I had it unbroken for 6 weeks before that.

So pissed off.

I wonder if the harmonics are letting your chain whip.

I’d be surprised if there wasn’t too much tension but it has that sound. All quite interesting.

What’s a copout is not being able to look at it for weeks, that’s just a lazy way of saying we have no ideas.

Dave!

V8Granite wrote: Tue Jul 15, 2025 9:27 am I wonder if the harmonics are letting your chain whip.

Is that the new Rhianna song?

The sound was the same before and after Scott had the tensioner replaced, so presumably not chain whip.

Depends whether they actually checked the chain for stretch or just stuck a new tensioner in and hoped for the best.

If the chain is stretched and the old tensioner was working fine it’ll make the same noise with a new one.

Or one of the guides has fallen apart or something.

Certainly sound chain or chain driven item related. Some older bmws used to have problems with the chain driving the oil pump. Don’t know if that engine has one of those.

Tensioner, chain and guides were all changed.

Rich B wrote: Mon Jul 14, 2025 7:18 pmBlimey, you must understeer more than Nebpor in his M5! you’ve only had it about a month!

This forum has a long memory

Jobbo wrote: Tue Jul 15, 2025 9:52 am The sound was the same before and after Scott had the tensioner replaced, so presumably not chain whip.

If it’s due to the damper failing then it wouldn’t matter at all. It would do it whatever.

This is assuming the tensioner isn’t quite strong enough.

Dave!

V8Granite wrote: Tue Jul 15, 2025 10:52 am

Jobbo wrote: Tue Jul 15, 2025 9:52 am The sound was the same before and after Scott had the tensioner replaced, so presumably not chain whip.

If it’s due to the damper failing then it wouldn’t matter at all. It would do it whatever.

This is assuming the tensioner isn’t quite strong enough.

Dave!

New Main chain tensioner fitted, New Oil pump tensioner fitted. Both chains replaced with new chains, All guides replaced with new guides. VVT cam pulleys not replaced. This seems to be the next logical step after discussions with other techs (Not at renault).

I'm going to speak to Rentec today and see if they will take it on. I can't leave it at renault on a "Maybe we'll look at it sometime but could be weeks"

The interesting thing is that the engine runs fine until it seems to switch over to another profile - 1:40 in the video. Im taking from that its not actual engine components like valves / Cam. Noise is definitely top end - i could feel the vibration by touching the engine mount you can see me do that in the video. so i'm ruling out pistons / crank. Oil was not sparkly. Filter was thrown out so unsure if that was checked.

Only code its thrown was a "P0300 random misfire multiple cylinders" which also fits with a timing issue.

We looked up the cost of the pulleys last night on my brothers parts system. £notcheap. Pulleys are controlled by oil pressure and solenoids so its possible it could be a solenoid.

ETA - I have managed to speak to the master tech at the Alpine dealer. They have never seen or had an engine issue with these cars. The only other similar thing that has been seen was a stretched chain on a Clio RS Turbo. We've ruled that out.

The noise starting at 1:40 also makes me think it wouldn’t be something internal. Usually if an engine is fucked internally it’s most noisy right at startup and gets slightly better as oil circulates but that’s just my guess.
Surely it isn’t beyond the wit of a competent technician to plug the engine ecu into a professional diagnostic machine which will tell them exactly what component turns on at 1:40 to go on from there

The "maybe" and "weeks" is a disgrace. Is this like one of these things where they only have a small subset of trained Alpine techs who can look at it?

I think Alfa did that with the 4C. Not all garages had trained techs.

I'm guessing there's not much in the way of used parts availability (for at least a/b testing the VVC guts) given how rare these cars are? Maybe you'll get lucky and the local specialist will have one they can borrow a set from that isn't moving for a while....

It definitely sounds like it's VVC related though, and it's only showing up once it comes out of it's fixed "emissions control" phase from cold start, and starts going into "fully adjustable" mode once it's warm.

scotta wrote: Tue Jul 15, 2025 11:31 am

V8Granite wrote: Tue Jul 15, 2025 10:52 am

Jobbo wrote: Tue Jul 15, 2025 9:52 am The sound was the same before and after Scott had the tensioner replaced, so presumably not chain whip.

If it’s due to the damper failing then it wouldn’t matter at all. It would do it whatever.

This is assuming the tensioner isn’t quite strong enough.

Dave!

New Main chain tensioner fitted, New Oil pump tensioner fitted. Both chains replaced with new chains, All guides replaced with new guides. VVT cam pulleys not replaced. This seems to be the next logical step after discussions with other techs (Not at renault).

I'm going to speak to Rentec today and see if they will take it on. I can't leave it at renault on a "Maybe we'll look at it sometime but could be weeks"

The interesting thing is that the engine runs fine until it seems to switch over to another profile - 1:40 in the video. Im taking from that its not actual engine components like valves / Cam. Noise is definitely top end - i could feel the vibration by touching the engine mount you can see me do that in the video. so i'm ruling out pistons / crank. Oil was not sparkly. Filter was thrown out so unsure if that was checked.

Only code its thrown was a "P0300 random misfire multiple cylinders" which also fits with a timing issue.

We looked up the cost of the pulleys last night on my brothers parts system. £notcheap. Pulleys are controlled by oil pressure and solenoids so its possible it could be a solenoid.

ETA - I have managed to speak to the master tech at the Alpine dealer. They have never seen or had an engine issue with these cars. The only other similar thing that has been seen was a stretched chain on a Clio RS Turbo. We've ruled that out.

I wonder if you can bench test the pulleys ?

I’d definitely be looking at something that alters what tension the chain sees. Which is anything to do with harmonics.

Dave!

Sorry to hear Renault UK are giving you the full Gallic experience Scotta!

This is a long shot but it's my bet - I wonder if one of the oil-ways is getting blocked up with some debris or dislodged sealant. Sounds like something is being starved of oil all of a sudden.

That treatment is shocking - imagine if it was your only car. Are they still trying to weasel out of responsibly?

Its at my brothers Renault dealer. Im getting his staff discount on the labour rates - hence the no urgency. They are not an Alpine dealer but then this is not an Alpine specific engine. Its out of a megane RS280/300 so i thought this was a good place to take it.

I have today arranged for it to go to Rentec. They can look at it a week on friday.

They think either VVC pulleys or oil starvation to the pulleys caused by the actuator solenoids. Their first plan is to remove the solenoids and test them then remove the access hatch and check the oilways. I had thought of the fuck it and replace them anyway option...But they are on backorder from renault.

scotta wrote: Tue Jul 15, 2025 2:34 pm Its at my brothers Renault dealer. Im getting his staff discount on the labour rates - hence the no urgency. They are not an Alpine dealer but then this is not an Alpine specific engine. Its out of a megane RS280/300 so i thought this was a good place to take it.

I have today arranged for it to go to Rentec. They can look at it a week on friday.

They think either VVC pulleys or oil starvation to the pulleys caused by the actuator solenoids. Their first plan is to remove the solenoids and test them then remove the access hatch and check the oilways. I had thought of the fuck it and replace them anyway option...But they are on backorder from renault.

Simon wrote: Tue Jul 15, 2025 1:42 pm This is a long shot but it's my bet - I wonder if one of the oil-ways is getting blocked up with some debris or dislodged sealant. Sounds like something is being starved of oil all of a sudden.

You're welcome.

More digging - this fits with solenoid failure. ChatGPT output


On the 1.8 L turbo engine (or modern Renault/Alpine 4‑cylinder with DOHC DVVT), the VVT (camshaft timing) system uses two primary solenoids:

1. **Intake camshaft solenoid** – controls oil flow to advance or retard the intake cam timing
2. **Exhaust camshaft solenoid** – same function, but for the exhaust camshaft

These two are what's shown on PATS or factory diagrams—they’re the essential actuators the ECU manipulates to adjust valve timing at different RPMs or loads (especially between cold and warm conditions).

---

### Why are three solenoids physically present?

Many owners find **three solenoids fitted to the head**, and this can be confusing. Here’s why:

* The **two “working” solenoids** (liftable from diagrams as Intake and Exhaust) are used dynamically during running to fine-tune cam timing throughout the RPM range.
* The **third solenoid** is typically a **bypass/park solenoid** (or “safety” solenoid). Its role is to provide a **default oil path** to the fixed cam phasers at startup or oil pressure loss—ensuring no cam phasers are left in odd positions.

This configuration ensures that on a **cold start**, the intake and exhaust solenoids may not be active until the engine reaches operating temperature or specific RPM, while the third lets the phasers "park" or remain safe.

---

### Cold Start Operation: Sequence Overview

1. **Key-on, engine off**
ECU performs self-checks but no oil pressure yet.

2. **Crank & start (cold)**
Primary intake and exhaust VVT solenoids remain **inactive**; ECU aims for fixed/default cam timing for emissions and cold idling.
The **third solenoid** (park/bypass) ensures oil pressure can still reach both cam phasers.

3. **Oil pressure builds (\~700–900 RPM)**
Once adequate, ECU may activate intake or exhaust solenoids to optimize idle and torque.

4. **Engine warming / accelerating**
ECU begins varying valve timing—activating intake and exhaust solenoids per load/RPM.

---

### Summary Table

| Purpose | Which Solenoid(s) |
| -------------------------------- | ----------------------- |
| **Diagram listing** | Intake & Exhaust |
| **Physical actuators present** | Intake, Exhaust, Bypass |
| **Cold start oil routing** | Bypass solenoid |
| **Variable timing (warm, load)** | Intake & Exhaust |

---

### Why the confusion?

* The **PATS engine diagrams** are schematic—they only illustrate functional solenoids in active control.
* On the actual head, a **third solenoid** is needed for reliable oil flow and safe cam phaser positioning on startup.

---

### TL;DR

* **Two solenoids** (intake and exhaust) do dynamic timing control.
* **Third solenoid** ensures default oil flow at cold start or if primary solenoids are inactive—acting as a failsafe.
* Diagrams show only the two primary ones, but the extra on the engine is critical to proper operation.

---

If you're chasing a particular symptom or fault code on your A110 (e.g. limp-home mode, cam timing error), it’s essential to check **all three** solenoids—especially the bypass unit, which is often overlooked.

Want a deep dive into cam phaser operation or specific wiring plugs? Happy to dig into wiring diagrams or step-by-step diagnostics.